Definitions

atropous

Glossary of botanical terms

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A

  • abaxial: the side away from the axis, e.g. the lower surface of a leaf.
  • abort: to abandon development of a structure of organ.
  • abscission: (adjective abscissile): a plant's normal shedding of an organ that is mature or aged, e.g. a ripe fruit or an old leaf.
  • -aceae: the suffix added to the stem of a generic name to form the name of a family.
  • achene: a dry 1-seeded indehiscent fruit; e.g. members of the Ranunculaceae.
  • acicular: slender or needle-shaped.
  • actinomorphic: regular; radially symmetrical; may be bisected into similar halves in at least two planes. Generally applies to flowers in which the perianth segments within each whorl are alike in size and shape; cf. irregular, regular, zygomorphic.
  • aculeate: armed with prickles; e.g. the stem of a rose.
  • acuminate: tapering gradually to a point.
  • acute: sharply pointed; converging edges making an angle of less than 90°; cf. obtuse.
  • adaxial: the side next to the axis; e.g. the upper surface of a leaf.
  • adnate: fused to an organ of a different kind; e.g. a stamen fused to a petal; cf. connate.
  • adventitious: a structure produced in an abnormal position; e.g. an adventitious bud produced from a stem rather than from the axil of a leaf.
  • adventive: introduced accidentally (usually referring to weeds).
  • aerial: of the air; growing or borne above the surface of the ground.
  • aestivation: the arrangement of sepals and petals or their lobes in an unexpanded flower bud; cf. vernation arrangement of leaves in a bud.
  • affinis (aff.): with affinity to others, akin to; often used for a provisionally recognized but unnamed taxon considered close to that name, perhaps a hybrid or extreme variant.
  • aggregate fruit: a cluster of fruits formed from the free carpels of one flower, e.g. blackberry; cf. multiple fruit.
  • agricultural weed: see weed.
  • -ales: suffix to the stem of a generic name or descriptive name to indicate that it applies to a taxon of the rank of order.
  • alien: differing in nature, foreign; a plant introduced from elsewhere (exotic, introduced, non-native, non-indigenous).
  • alkaloid: molecule with a nitrogenous base, many used as drugs; e.g. morphine, quinine, strychnine.
  • alternate: (as adjective) leaves or flowers borne singly at different levels along a stem includes spiralled parts; or (as verb) when something occurs between something else, e.g. stamens alternating with petals; cf. opposite.
  • amphitropous: when the ovule is bent so that both ends are near each other; cf. anatropous, campylotropous, orthotropous.
  • amplexicaul: with the base dilated and clasping the stem, usually of leaves.
  • anastomosing: when veins are joined by cross-veins to form a network.
  • anatropous: when an ovule is inverted so that the micropyle faces the placenta (this is the most common ovule orientation in flowering plants); cf. amphitropous, campylotropous, orthotropous.
  • androdioecious: of plants, having bisexual flowers and male flowers on separate individuals; cf. andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
  • androecium: male parts of flower; the stamens of a flower collectively; cf. gynoecium.
  • androgynophore: a stalk bearing both the androecium and gynoecium of a flower above the level of insertion of the perianth.
  • androgynous: with male and female flowers in the same inflorescence.
  • andromonoecious: of plants, having bisexual and male flowers on the same individual; cf. andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
  • angiosperms: 'flowering plants'; plants with developing seeds enclosed in an ovary.
  • annual: a plant that completes its life cycle and dies within one year.
  • anterior: away from the axis; usually abaxial.
  • anther: pollen-bearing part of the stamen.
  • anthesis: time of flowering; the stage at which the pollen is released from the anthers inside the bud onto the pollen presenter, usually corresponding with flower opening.
  • antrorse: directed towards or upwards, e.g. of hairs on a stem; cf. retrorse.
  • apex (apical): the tip; the point furthest from the point of attachment; plural apices.
  • apiculate: terminating in a short sharp flexible point; less abrupt than mucronate.
  • apocarpous: of a gynoecium consisting with one or more carpels which are free from one another (or almost so); e.g. Ranunculaceae, Dilleniaceae.
  • apomixis: reproduction, where viable seed or spores are produced without fertilization. A plant produced in this way is an apomict.
  • appendage: a secondary part attached to the main structure; an external growth that seldom has any obvious function.
  • appressed: pressed closely, but not fused; e.g. leaves against a stem.
  • aquatic: plants whose natural habitat is water; i.e. living in or on water for all or a substantial part of the organism's life span, generally restricted to fresh or inland waters.
  • arborescent: tree-like in growth or general appearance.
  • arboretum: (plural arboreta) a taxonomically arranged collection of trees.
  • areole: (from areola) a space between the threads of a net; e.g. that part of a leaf surface defined by each of the elements of a vein network; as with cacti, the area between the veinlets of a leaf or the region of a cactus bearing the flowers and/or spines.
  • aril (adjective arillate): a membranous or fleshy appendage (formed by expansion of the funicle) which partly or wholly covers a seed; e.g. the fleshy outer layer of lychee fruit and as found in Sapindaceae.
  • aristate: with a stiff, bristle-like awn or tip.
  • article: a segment of a jointed stem or of a fruit with constrictions between the seeds; an organ part that separates easily from the rest of the organ at a joint or articulation.
  • articulate: jointed; separating freely, leaving a clean scar; e.g. the fronds of certain ferns where they join the rhizome.
  • ascending: spreading horizontally, then becoming erect.
  • asexual: of reproduction that does not involve the gametes; i.e. vegetative reproduction.
  • attenuate: narrowing gradually.
  • auricle (adjective auriculate): ear-shaped lobe.
  • awn: fine bristle-like appendage; e.g. terminating or on the back of glumes and/or lemmas of some grass spikelets.
  • axil: the upper angle between one part of a plant and another; e.g. the stem and a leaf.
  • axile: on an axis; of a placenta, on the central axis of the ovary.
  • axillary: borne in or arising from the axil of a leaf.*
  • axis: a line passing through the centre of something; it usually refers to the main stem of a whole plant or inflorescence.

B

  • bark: the protective external layer of tissue on the stems and roots of trees and shrubs; includes all of the living and non-living tissue external to the cambium.
  • basal: at the base, situated or attached at the base.
  • basifixed: something attached by its base; e.g. an anther attached to the filament.
  • basipetal: developing sequentially from the apex towards the base (i.e. with the youngest towards the base); e.g. of flowers in an inflorescence.
  • beak: a pointed projection.
  • berry: an indehiscent fruit, with the seeds immersed in the pulp, e.g. tomato.
  • biennial: plant which completes its life cycle and dies within the second year; usually also forms a basal rosette of leaves the first year and flowers and fruits the second year.
  • bifid: forked; cut in two for about half its length.
  • bilabiate: having two lips; e.g. the form of the petals in many irregular flowers.
  • bilateral: arranged on opposite sides; e.g. leaves on a stem.
  • binomial: making use of names consisting of two words to form the scientific name (or combination) in a Latin form. For example, where the first is the name of the genus to which the species belongs, and the second is the epithet given to that species to distinguish it from others in the same genus.
  • binomial nomenclature: the system of nomenclature in which the scientific name of a species (and not of a taxon at any other rank) is a combination of two names, the first name being the generic name. The second name is referred to botanically as the specific epithet. Note that the two names constitute the species name, not just the second word.
  • bipinnate: twice pinnate; e.g. of a compound leaf with individual leaflets pinnately divided.
  • bipinnatisect: a pinnatisect leaf with deeply dissected segments.
  • bisexual: bearing both male and female reproductive organs; usually, flowers with both stamens and carpels; hermaphrodite.
  • bole: the trunk of a tree, usually below the lowest branch; cf. canopy.
  • blade: the lamina or flattened part of a leaf, excluding the stalk.
  • bloom: a fine white or bluish waxy powder occurring on plant parts, usually stems, leaves and fruits. It is easily removed by rubbing.
  • bract: modified leaf associated with flower or inflorescence, differing in shape, size or colour from other leaves (and without an axillary bud).
  • bracteole: small bracts borne singly or in pairs on the pedicel or calyx.
  • branchlet: a small branch.
  • bristle (adjective: bristly): straight stiff hair (smooth or with minute teeth) or upper part of an awn (when the latter is bent and has a lower, stouter, and usually twisted part, called the column).
  • bryophyte: a botanical group including mosses and liverworts. Technically a classification of plants including three classes: hornworts (Anthocerotae), liverworts (Hepaticae) and mosses (Musci).
  • bulb: thick storage organ, usually underground, consisting of a stem and leaf bases (the inner ones fleshy).
  • bulbel: a bulb arising from another bulb.*
  • bulbil: small deciduous bulb or tuber formed in the axil of a leaf or pinna; a means of vegetative propagation.
  • bulblet: a bulb arising from another bulb; a bulbil.
  • bullate: blistered or puckered.
  • burr: loosely, a prickly fruit; a rough or prickly propagule consisting of a seed or fruit and associated floral parts or bracts.
  • buttress root: a root growing from the above-ground stem or trunk, and providing support, as in the case of Ficus macrophylla, the Moreton Bay Fig.

C

  • caducous: falling off early; cf. persistent.
  • caespitose: tufted; e.g. the growth form of some grasses.
  • callus (plural calli): generally, a protruding mass of tissue; in orchids, fleshy outgrowths from the labellum which can be variously shaped from papillae to plates; in grasses, hardened extension from the base of a floret (formed from the rachilla joint and/or the base of the lemma) which may or may not elongate and is often covered in hairs or bristles.
  • calyptra: a hood or lid; see operculum.
  • calyx (plural calyces): the outer whorl of a flower, usually green; the sepals of one flower collectively.
  • calyx tube: a tube formed by the fusion of the sepals (calyx), at least at the base.
  • campanulate: bell-shaped.
  • campylotropous: when the ovule is oriented transversely (i.e. with its axis at right angles to its stalk) and with a curved embyro sac; cf. amphitropous, anatropous, orthotropous.
  • canaliculate: channelled; with a longitudinal groove.
  • canopy: the branches and foliage of a tree; crown; cf. trunk.
  • capillary: (noun) a tube, pore or passage with a narrow internal cross-section; (adjective) slender, hair-like.
  • capitate: with knob-like head; of an inflorescence, with the flowers unstalked and aggregated into a dense cluster; of a stigma, like the head of a pin.
  • capitulum: a dense cluster of sessile, or almost sessile, flowers or florets; a head.
  • capsule: a dry fruit formed from two of more united carpels and dehiscing when ripe (usually by splitting into pieces or opening at summit by teeth or pores).
  • carina (adjective carinate): keel.
  • carpel: a female organ borne at the centre of a flower, consisting of an ovary, a style and a stigma. The gynoecium is the collective term for all the carpels of a single flower.
  • cartilaginous: hard and tough; gristly.
  • caryopsis: a dry, indehiscent, one-seeded fruit in which the seed coat is closely fused to the fruit wall, as in most grasses.
  • casual alien: a plant that appears with no apparent human assistance but does not develop a sustained population(s). Plants that persist only by new introductions; cf. alien.
  • catkin: a spike, usually pendulous, in which the mostly small flowers are unisexual and without a conspicuous perianth; e.g. willows, poplars, oaks and casuarinas. The individual flowers often have scaly bracts; they are generally wind-pollinated. The catkins are usually shed as a unit.
  • caudate: having a narrow tail-like appendage.
  • cauline: borne on an aerial stem, e.g. leaves, flower or fruits (when applied to the latter two organs, usually referring to older stems; = cauliflorous).
  • cell: (1) basic (microscopic) unit of plant structure, generally consisting of compartments in a viscous fluid surrounded by a wall; (2) cavity of an anther or ovary.
  • centrifixed: of a two-branched organ attached by its centre, e.g. a hair, or anther.
  • chartaceous: with a papery texture.
  • chamber: cavity of an ovary.
  • chasmogamous: of flowers that are pollinated when the perianth is open; cf. cleistogamous.
  • chimaera: an individual composed of two or more genetically different tissues, most commonly as a result of a graft and sometimes within the individual, by mutations and irregularities that occur during cell division.
  • chlorophyll: a green pigment in chloroplasts, essential for photosynthesis.
  • chloroplast: an organelle present in plant cells that contains chlorophyll.
  • cilia (singular cilium, adjective ciliate): generally, hairs more or less confined to the margins of an organ, like eye-lashes; in motile cells, minute, hair-like protrusions which aid motility.
  • circinate (circinnate): spirally coiled with the tip innermost; e.g. the developing fronds of most ferns.
  • cladode: a photosynthetic stem, often leaf-like and usually with foliage leaves either absent or much reduced; cf. phyllode.
  • class: the principal category for taxa in a rank between division and order.
  • clathrate: latticed or pierced with apertures.
  • clavate: club-shaped.
  • claw: (1) narrow, stalk-like basal portion of petal, sepal of bract; (2) in Melaleuca, the united portion of a stamen bundle.
  • cleistogamous: of flowers that self-pollinate and never open fully, or self-pollinate before opening; cf. chasmogamous.
  • climber: a plant growing more or less erect by leaning or twining on another structure for support.
  • cline (adjective clinal): continuous morphological variation in form within a species or sometimes between two species.
  • clone: plants derived from the vegetative reproduction of an individual, all having the same genetic constitution.
  • coalescent: plant parts fused or grown together to form a single unit.
  • columella: in flowering plants, the central axis of the cone or fruit, e.g. in Callitris.
  • column: (1) structure extending above ovary and incorporating the style and stamens; gynostemium; e.g. in orchids; (2) in grasses, the lower, stouter, and usually twisted part of an awn, distinct from the slender upper part or bristle.
  • columnar: shaped like a column.
  • commercial name: a name often of no botanical standing and not governed by the ICNCP. The term generally applies to names such as Trademark Names, names covered by Plant Breeders Rights, Patents and Promotional Names; often used to enhance the sale of a plant.
  • community: an assemblage, in nature, of plants that characteristically occur together.
  • compound: composed of several parts, e.g. a leaf with leaflets, a gynoecium with several carpels, or an inflorescence made up of smaller inflorescences.
  • compressed: flattened lengthwise, either laterally (from side to side) or dorsally (from front to back).
  • concolorous: the same colour throughout.
  • cone: a fruit, usually woody, ovoid to globular, including scales, bracts or bracteoles arranged around a central axis, e.g. in gymnosperms, especially conifers and Casuarina.
  • conflorescence: of an inflorescence when the overall structure substantially differs from that of its individual flowers; e.g. the bottlebrush multiple -flower head of callistemons.
  • connate: fused to another organ (or organs) of the same kind; e.g. petals in a floral tube; cf. adnate.
  • connective: the part of an anther that connects the anther cells.
  • connivent: coming into contact or converging.
  • conspecific: belonging to the same species.
  • contiguous: adjoining, touching, but not united.
  • contorted: twisted out of the normal shape.
  • convolute: referring to the arrangement of floral or foliar organs in a bud when each organ or segment has one edge overlapping the adjacent organ or segment; a form of imbricate arrangement; contorted.
  • cordate: heart-shaped, with the notch lowermost; of the base of a leaf, like the notched part of a heart.
  • coriaceous: leathery; stiff and tough, but somewhat flexible.
  • corm: fleshy, swollen stem base, usually underground, storing food reserves, with buds naked or covered by very thin scales; a type of rootstock.
  • corolla: collective term for the petals of a flower.
  • corona (adjective:coronate): literally, crown; (1) in flowering plants, ring of tissue arising from the corolla or perianth of a flower and standing between the perianth lobes and the stamens; e.g. the daffodil trumpet, passionfruit; (2) in grasses, a hardened ring of tissue surmounting the lemma in some species.
  • corymb (adjective corymbose): inflorescence with branches arising at different points but reaching about the same height, giving the flower cluster a flat-topped appearance.
  • costa (adjective costate): a rib.
  • cotyledon: primary leaf or leaves of an embryo, becoming the seed leaf or leaves.
  • crenate: with blunt or rounded teeth, scalloped.
  • crenulate: minutely scalloped.
  • crisped: finely curled. A term generally applied to the edges of leaves and petals.
  • crown: see canopy.
  • cross: to make something interbreed; the act of hybridization.
  • cruciform: cross-shaped.
  • crustaceous: hard, thin and brittle.
  • cryptogams: ferns, bryophytes, algae and fungi (including lichenized fungi); 'lower plants'; plants producing spores, and without stamens, ovaries or seeds, literally plants whose sexual reproductive organs are not conspicuous cf. phanerogam.
  • culm: in grasses, sedges, rushes, and some other monocotyledons, an aerial stem bearing the inflorescence; strictly, from the base of the plant to the lowest involucral bract (or base of the inflorescence).
  • cultigen: a plant whose origin or selection is primarily due to intentional human activity.
  • cultivar: the term cultivar is derived from cultivated variety and denotes an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical or other); when reproduced (sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant of horticultural interest or value. Cultivar names are written with single quotation marks around them e.g. 'Blue Carpet', 'Alba'. All new names established after 1 January 1959, must be in common language (that is, not in Latin) but names established in Latin prior to this date are retained in Latin form.
  • cultivar epithet: the defining part of a name that denominates a cultivar. Cultivars are designated by fancy (q.v.) epithets appended either to the scientific name or to the common name of the taxon to which they belong; they are not italicized but placed in single quotation marks, for example Rubus nitidoides 'Merton Early'. 'Merton Early' is the cultivar epithet.
  • cuneate: wedge-shaped; with straight sides converging at base.
  • cuspidate: tipped with a cusp.
  • cutting: a piece of plant, usually an apical tip of shoot structure but may be root or leaf, cut from plant and used for vegetative propagation.
  • cyathium: an inflorescence of unisexual flowers surrounded by involucral bracts, e.g. the flowers of Euphorbia.*
  • cyme (adjective cymose): inflorescence in which the main axis and all lateral branches end in a flower (each lateral may be repeatedly branched).
  • cypsela: a dry, indehiscent, one-seeded fruit formed from an inferior ovary.

D

  • deciduous: falling seasonally, e.g. bark, leaves, petals; cf. persistent.
  • decorticate: to shed or peel off the outer bark of a tree.
  • decumbent: with branches growing horizontally but turned up at the ends.
  • decurrent: extending downwards beyond the point of exsertion, e.g. when the base of a leaf is prolonged downwards along the stem in a raised line or narrow wing.
  • decussate: opposite, with successive pairs borne at right angles to the last; generally applied to the arrangement of leaves.
  • definite: of a constant number; e.g. twice as many stamens as the petals or sepals (or less), or an inflorescence ending in a flower or an aborted floral bud, typically a cymose inflorescence; cf. indefinite.
  • deflexed: bent downwards; cf. inflexed.
  • dehiscent: breaking open at maturity to release contents. Generally refers to the release of seed from some fruits; also pollen from anthers.
  • deltoid: with the shape of the Greek letter, i.e. like an equilateral triangle.
  • dendroid: tree-like, branching like a tree.
  • dentate: toothed.
  • denticulate: finely toothed.
  • determinate: limited, usually in growth.
  • dichasium: a cymose inflorescence with all branches below the terminal flower in regular opposite pairs; cf. monochasium.
  • dicotyledon: a flowering plant whose embryo has two (rarely more) cotyledons (seed leaves) (common usage - dicot.) cf. monocotyledon (common usage - monocot.).
  • dichotomous: forking into two equal branches, resulting from an equal division of the growing tip.
  • digitate: with segments spreading from a common centre, like the fingers of a hand; see also palmatisect.
  • dimorphic (dimorphous): of 2 different kinds (in respect to shape and/or size), e.g. stamens, fronds, leaves.
  • dioecious: of plant, when male and female reproductive structures develop on different individuals; of infloresence, male and female flowers in separate infloresences; cf. monoecious.
  • diploid: with two full sets of chromosomes in the nucleus of a cell; having two complements of haploid chromosomes, that is the two complete sets of chromosomes, one from each of the parental gamete. This is expressed symbolically as 2n, where n = the gamete number of chromosomes.
  • disk (disc): a plate or ring of structures derived from the receptacle, and occurring between whorls of floral parts: in daisies, the central part of capitulum, hence disk flowers or florets.
  • discolorous: of leaves, with upper and lower surfaces of a different colour.
  • disjunct: occurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations far enough as to preclude gene flow between them.
  • dissected: deeply divided; cut into many segments.
  • distal: remote from the point of origin or attachment; the free end; cf. proximal.
  • distichous: arranged in two opposite rows (and hence in the same plane).
  • distinct: separate or free, not united.
  • diurnal: of the day; occurring or opening in the daytime.
  • divaricate: wide-spreading.
  • divergent: spreading in different directions, generally upward.
  • division: the term used for the rank below kingdom in the taxonomic hierarchy.
  • domatia: pits formed at the junction of two veins on the undersurface of leaves (mostly of rainforest plants); often modified appendages that shelter parasites and other micro-organisms.
  • dorsal: the back; at the back; in particular, away from the axis in a lateral organ or away from the substratum in a prostrate plant.
  • dorsifixed: attached at or by the back, e.g. anthers on a filament.
  • dorsiventral: having structurally different upper and lower surfaces, e.g. some leaves.
  • drupe: a succulent fruit formed from one carpel; the single seed is enclosed by a stony layer of the fruit wall; kernel; e.g. peaches, olives and the fruit of Nitraria billardieri.

E

  • ecological amplitude: the range of environmental conditions in which an organism can survive.
  • elaisome: oily body attached to the seed.
  • ellipsoid: a 3-dimensional shape, elliptical in all sections through the long-axis.
  • elliptical (elliptic): planar, shaped like a flattened circle, symmetrical about both the long and the short axis; about twice as long as broad, tapering equally both to the tip and the base; oval.
  • emarginate: notched at apex (notch usually broad and shallow).
  • embryo: young plant contained by a seed.
  • endemic: having a natural distribution restricted to a particular geographic region; cf. native.
  • endocarp: the innermost layer of the wall of a fruit; in a drupe, the stony layer surrounding the seed.
  • endosperm: nutritive tissue in a seed; albumen.
  • ensiform: shaped like the blade of a sword.
  • entire: having a smooth margin, not lobed, divided or toothed (it may be wavy or scalloped, but not incised).
  • ephemeral: short-lived.
  • epicalyx: an involucre resembling an outer calyx; e.g. as seen in Hibiscus.
  • epicarp: the outer layer of the wall of a fruit, i.e. the 'skin'.
  • epicormic: said of buds shoots or flowers developing from the old wood of trees, especially after injury or fire.
  • epicotyl: the part of the plant axis or stem between the cotyledonary node and first foliage leaves.
  • epidermis: an organ's outermost layer of cells, usually only one cell thick.
  • epigynous: borne on the ovary; describes floral parts when attached above the level of the ovary and arising from tissue fused to the ovary wall; cf. hypogynous, perigynous.*
  • epilithic: see lithophytic.
  • epipetalous: of stamens that are attached to the petals.
  • epitepalous: of stamens that are attached to the tepals.
  • epiphyte (adjective epiphytic): one plant growing on another without deriving nourishment from it (i.e. not parasitic); cf. parasite. Loosely, and incorrectly, applied to plants that are not terrestrial (i.e. they may grown on various inorganic or organic surfaces), and often to orchids, which are rock-dwelling (and therefore strictly lithophytic).
  • epithet: the adjectival component in a binomial; final word or combination of words in a name of more than one word (other than a term denoting rank) that denominates an individual taxon.
  • equitant: of a leaf when folded lengthwise with edges adhering except at the base, where it clasps another leaf on the opposite side of the stem.*
  • erect: upright, more or less perpendicular to the ground or point of attachment.
  • ericoid: with leaves like the European heath (Erica), small and sharply pointed.
  • erose: with the margin irregular as though nibbled or worn away.
  • evergreen: not deciduous, having leaves all the year round.
  • ex: in nomenclature, indicating that the preceding author proposed the name but did not legitimately publish it, and that the succeeding author referred to the first author when legitimately publishing the name.
  • exocarp: the outer layer of the pericarp, often the skin of fleshy fruits.
  • exotic: not native; introduced from another region or country.
  • exserted: projected beyond, e.g. the stamens beyond the corolla tube.
  • exstipulate: without stipules.
  • extrorse: of anther locules, opening towards the outside of the flower; cf. introrse, latrorse.

F

  • F1 hybrid: a single cross; a plant breeding term for the result of a repeatable cross between two pure bred lines.
  • F2 hybrid: a plant breeding term for the result of a plant arising from a cross between two F1 hybrids; may also refer to self-pollination in a population of F1 hybrids.
  • facultative: of parasites, optional; cf. obligate.
  • falcate: curved like the blade of a scythe.
  • family: a formal group of one or more genera with features and/or ancestry in common; the term for the principal rank between order and genus.
  • fascicle: (adjective fasciculate) cluster, e.g. a tuft of leaves all arising from the same node.
  • fastigiate: parallel, clustered and erect, e.g. the arrangement of branches in the Lombardy Poplar.
  • felted: covered with very dense, interlocked and matted hairs with the appearance or texture of felt or woollen cloth.
  • ferruginous: rust-coloured.
  • fertile: capable of producing fruit; of flowers when they produce seed or of anthers containing pollen.
  • fertilization: union of male and female gametes.
  • filament: (1) stalk of a stamen; (2) thread, one or a few cells thick.
  • filamentous: consisting of filaments or fibres.
  • filiform: thread-like.
  • fimbriate: fringed.
  • fissure: split or crack, often referring to fissured bark.
  • flabellate: fan-shaped.
  • flaccid: limp; tending to wilt; cf. turgid.
  • flexuous (flexuose): bent alternately in different directions; zig-zag.
  • floccose: with a soft and woolly covering of hairs.
  • flora: (1) all the plants growing in a certain region or country; (2) an enumeration of them, generally with a guide to their identification (e.g. the present volume, the Flora of Victoria, the Flora of New South Wales and so on). In this case 'flora' is written with a capital F.
  • floral leaves: the upper leaves at the base of the flowering branches.
  • floral tube: tube bearing the perianth and stamens, consisting of tissue derived from the receptacle and/or perianth and/or stamens; hypanthium.
  • floret: a small flower; usually refers to the flowers of the daisy and grass families.
  • flower: the sexual reproductive structure of the angiosperms, typically with a gynoecium, androecium, perianth and an axis.
  • follicle: a dry fruit formed from one carpel, splitting along a single suture, to which the seeds are attached; cf. pod (of legume).
  • forest: vegetation dominated by trees with single trunks (including closely arranged trees with or without an understorey of shrubs and herbs).
  • forma (in common usage, form): a taxonomic category subordinate to species and within the taxonomic hierarchy, below variety (varietas), usually differentiated by a minor character.
  • free: not united with others of the same organ; not attached at one end.
  • free central: of placentation, ovules attached to a free-standing column in the centre of a unilocular ovary.
  • frond: a leaf of a fern, cycad or palm.
  • fruit: seed-bearing structure in angiosperms formed from the ovary, and sometimes associated floral parts, after flowering.
  • funicle (funiculus): the stalk of an ovule.
  • funnelform: with a form gradually widening from the base to apex; funnel-shaped.
  • fused: joined together.
  • fusiform: 3-dimensional, narrowing gradually from the middle towards each end; spindle-shaped.

G

  • gamete: (in ferns, gymnosperms and angiosperms) a cell or nucleus that fuses with another of the opposite sex in sexual reproduction.
  • gametophyte: plant that bears gametes; in ferns, usually a small but discrete plant very different from the sporophyte (which is normally considered the fern plant); in gymnosperms and angiosperms, a microscopic structure (part of the reproductive apparatus) not recognizable as a discrete plant.
  • gene pool: the range of genetic variation found in a population.
  • genus (plural genera): a group of one or more species with features and/or ancestry in common. Genus is the principal category of taxa intermediate in rank between family and species in the nomenclatural hierarchy.
  • generic name: the name of a genus, e.g. Acacia, Eucalyptus.
  • genotype: the genetic make-up of an individual.
  • germination: (1) of seeds, describing the complex sequence of physiological and structural changes that occur from resting to growth stage. (2) of a pollen grain; production of a pollen tube when contacting a stigma receptive to it; (3) of a spore of fungi/bacterium; change of state - from resting to vegetative.
  • gibbous (gibbose): when part of an organ is swollen; usually with a pouch-like enlargement at base.
  • glabrescent: becoming glabrous, almost glabrous.
  • glabrous: without surface ornamentation such as hairs, scales or bristles.
  • gland: a secretory structure within or on the surface of a plant; (loosely) a smooth, usually shining, bead-like outgrowth.
  • glandular hair: hairs tipped with a gland.
  • glaucous: with a whitish bloom, blue-green in colour; e.g. the surface of the young leaves of many eucalypts.
  • globose (globular): nearly spherical.
  • globulose: small or nearly spherical.
  • glochid: a barbed hair or bristle, e.g. the fine hairs in Opuntia.
  • glumes: bracts subtending the floret(s) of a sedge, or similar plant; in grasses forming the lowermost organs of a spikelet (there are usually 2 but 1 is sometimes reduced; or rarely, both are absent).
  • glutinous: sticky.
  • graft: (1) of a plant, the artificial union of plant parts; (2) a plant shoot suitable for grafting; loosely means a scion, sucker, or branch; (3) an old word for a spade's depth of soil; (4) a kind of spade used for digging drains.
  • graft chimaera: a taxon whose members consist of tissue from two or more different plants in intimate association originated by grafting. The addition sign "+" is used to indicate a graft-chimaera either as a part of a formula (e.g. Crataegus monogyna + Mespilus germanica), or in front of an abbreviated name (e.g. + Crataemespilus gillottii).
  • granular: of a surface, covered with small rounded protuberances.
  • grass: a plant belonging to the family Poaceae.
  • grassland: low vegetation dominated by grasses.
  • groundcover: (1) of a plant, with a very flat and soil-hugging habit; (2) a term applied to describe a plant that covers the soil surface so densely that it smothers all beneath it.
  • Group: a formal category equivalent to or below the rank of genus. It distinguishes: (1) an assemblage of two or more cultivars within a species or hybrid; (2) plants derived from a hybrid in which one or more of the parent species is not known or is of uncertain origin; and (3) a range of cultivated plants of a species or hybrid which may exhibit variation but share one or more characters, which makes it worth distinguishing them as a unit.
  • gymnosperm: a seed-bearing plant with ovules borne on the surface of a sporophyll; includes, among others, conifers, Ginkgo, Gnetum and cycads.
  • gynobasic: of a style, arising near the base of the gynoecium, e.g. between the lobes of the ovary.
  • gynoecium: female parts of flower; the collective term for the carpels of a flower whether united or free; cf. pistil; androecium.
  • gynophore: stalk supporting the gynoecium (above the level of insertion of the other floral parts).

H

  • habit: the general external appearance of a plant, including size, shape, texture and orientation.
  • habitat: the place where a plant lives; the environmental conditions of its home.
  • hair: a single elongated cell or row of cells borne on the surface of an organ.
  • half-inferior: of ovary, partly below and partly above the level of attachment of the other floral parts; cf. inferior, superior.
  • halophyte: a plant adapted to living in highly saline habitats; a plant that accumulates high concentrations of salt in its tissues.
  • hand-pollination: the controlled act of pollination that excludes the possibility of open-pollination.
  • haploid: of chromosomes, and relative to the phase of an alternation of generations in which the duplicated chromosome set or diploid condition is reduced; the condition when the chromosomes are not duplicated, e.g. the complement of chromosomes in the nucleus of a gamete; a single basic set of chromosomes in the nucleus of a cell. This may be expressed symbolically as n, where n = the gamete number of chromosomes.
  • hastate: like the head of a halbert, i.e. narrow and pointed but abruptly enlarged at the base into two acute diverging lobes; may refer only to the base of a leaf with such lobes; cf. sagittate.
  • haustorium: in parasitic plants, a structure developed for penetrating the host's tissues.
  • head: see capitulum.
  • heathland: vegetation dominated by small shrubs which usually have ericoid leaves.
  • helicoid: coiled; of a cymose inflorescence, when the branching is repeatedly on the same side (the apex is often recurved); cf. scorpioid.
  • herb: a vascular plant that does not develop a woody stem; e.g. a violet.
  • herbaceous: not woody; usually green, and soft in texture.
  • herbarium: a collection of preserved, usually dried, plant material. Also a building in which such collections are stored.
  • hermaphrodite: see bisexual.
  • heteromorphic: of 2 or more distinct morphologies (e.g. of different size and shape).
  • hilum: the scar on a seed coat where it separates from its stalk (funicle).
  • hip: the fruit of a rose.
  • hirsute: bearing coarse, rough, longish hairs.
  • hispid: having long erect rigid hairs or bristles, harsh to touch.
  • hoary: covered with a greyish to whitish layer of very short, closely interwoven hairs, giving a frosted appearance.
  • holotype: a type chosen by the author of a name; cf. a lectotype, which is chosen by a later author.
  • hort.: (never capiltalised) of gardens, an author citation used in two ways: (1) as a name misapplied by gardeners and (2) as an invalid name derived from horticultural writings of confused authorship.
  • hyaline: translucent; usually delicately membranous and colourless.
  • hybrid: a plant produced by the crossing of parents belonging to two different named groups, e.g. genera, species, varieties, subspecies, forma and so on; i.e. the progeny resulting within and between two different plants. An F1 hybrid is the primary product of such a cross. An F2 hybrid is a plant arising from a cross between two F1 hybrids (or from the self-pollination of an F1 hybrid).
  • hybrid formula: the names of the parents of a hybrid joined by a multiplication sign, e.g. Cytisus ardonoi × C. purgans.
  • hypanthium: see floral tube.
  • hypogynous: borne below the ovary; used to describe floral parts inserted below the ovary's level of insertion; cf. epigynous, perigynous.
  • hypocotyl: of an embryo or seedling, the part of the plant axis below the cotyledon and node, but above the root. It marks the transition from root to stem development.

I

  • illegitimate name: a name not abiding by the rules of the botanical Codes, e.g. cultivars that have been Latinised after 1 Jan 1959; cultivar names with more 10 syllables or 30 letters; cultivar names that use confusing names of other plants, e.g. Camellia 'Rose'.
  • imbricate: overlapping each other; of perianth parts, edges overlapping in the bud (the convoluted arrangement is a special form of imbrication).
  • imparipinnate: a pinnate leaf with an odd number of pinnae (terminated by a single leaflet); cf. paripinnate.
  • in: in nomenclature, where the preceding author published the name in an article or book, authored or edited by the succeeding author.
  • inbreeding: the production of offspring between closely related parents leading to a high degree of similarity; self-fertilization is the most intense form of inbreeding.
  • incised: cut deeply and (usually) unevenly (a condition intermediate between toothed and lobed).
  • included: enclosed, not protruding; e.g. stamens within the corolla.
  • incurved: bent or curved inwards; of leaf margins, when curved towards the adaxial side.
  • indefinite: variable in number; numerous; e.g. more than twice as many stamens as petals or sepals, or when an inflorescence is not terminated by a flower (and continues growing); cf. definite.
  • indehiscent: not opening in any definite manner at maturity; usually referring to fruit.
  • indeterminate: unlimited, usually in growth.
  • indigenous: native to the area, not introduced, and not necessarily confined to the region discussed (hardly distinct from ‘native’ but usually applied to a smaller area). For example, the Cootamundra Wattle is native to Australia but indigenous to the Cootamundra region of southern New South Wales; cf. endemic.
  • indumentum: any surface covering, e.g. hairs, scales; a collective term for such coverings.
  • indusium: (1) a membrane covering the sporangia of some ferns; (2) a cup enclosing the stigma in Goodeniaceae.
  • inferior: of an ovary, at least partly below the level of attachment of other floral parts; cf. superior.
  • inflated: swollen, like a bladder.
  • inflexed: bent sharply upwards or forwards; cf. deflexed.
  • inflorescence: several flowers closely grouped together to form an efficient structured unit; the grouping or arrangement of flowers on a plant.
  • infraspecific: denotes taxonomic ranks below species level, e.g. subspecies.
  • infructescence: the grouping or arrangement of fruits on a plant.
  • infundibular (infundibularform): funnel-shaped.
  • inrolled: rolled inwards.
  • insectivorous: catching, and drawing nutriment from, insects.
  • interjugary glands: in pinnate leaves, glands occurring along the leaf rachis between the pinnae (occurring below the single, and often slightly larger, gland at or just below the insertion of the pinnae); cf. jugary.
  • internode: the portion of a stem between two nodes.
  • interpetiolar: of stipules, between the petioles of opposite leaves.
  • intramarginal: inside but close to the margin, e.g. a vein in a leaf.
  • introrse: of anther locules, with opening towards the centre of flower (at least in bud); cf. extrorse, latrorse.
  • invalid: use of names not validly published according to the Code; i.e. they are not strictly 'names' in the sense of the International Code of Botanical Nomenclature.
  • involucre: a group of bracts surrounding the base of a flowerhead; e.g. as seen in a daisy.
  • involute: rolled inwards, e.g. when the margins of a leaf are rolled towards the adaxial (usually upper) surface; cf. revolute.
  • irregular: cannot be divided into two equal halves through any vertical plane; cf. zygomorphic, actinomorphic, regular.

J

  • joint: a node or junction of two parts; articulation.
  • jugary: of glands, gland occurring on the rachis of a bipinnate leaf at the junction or attachment of pairs of pinnae or pinnules, as in some Acacia species; cf. interjugary.
  • juvenile leaves: formed on a young plant and different in form from the adult leaves.

K

  • keel: a ridge like the keel of a boat, e.g. the structure formed by the fusion of the two anterior petals of a flower in the Fabaceae.
  • kernel: see drupe.
  • kingdom: the highest generally employed category of the taxonomic hierarchy, above that of division (phylum).

L

  • labellum: lip; one of three or five petals which is (usually) different from the others, e.g. in Orchidaceae and Stylidiaceae.
  • labiate: lipped; where the limb of a corolla is divided into two parts, called an upper and lower lip, the two resembling an open mouth with lips.
  • lacerate: jagged, as if torn.
  • laciniate: slashed into narrow, pointed lobes.
  • lamella (plural lamellae, adjective lamellate): a thin, plate-like layer.
  • lamina: the blade of a leaf or the expanded upper part of a petal, sepal or bract.
  • lanceolate: about four times as long as broad, broadest in the lower half and tapering to the tip; narrowly ovate (sometimes, and incorrectly, used to mean narrowly elliptic; like a lance head).
  • lateral: attached to the side of an organ, e.g. leaves on a stem.
  • latex: a milky substance that exudes from such plants such as milk thistles, figs and dandelions.
  • lax: loose, not compact.
  • leaf: an outgrowth of a stem, usually flat and green; its main function is food manufacture by photosynthesis.
  • leaflets: the ultimate segments of a compound leaf.
  • legume: (1) a fruit characteristic of the families Mimosaceae, Caesalpiniaceae and Fabaceae, formed from one carpel and either dihiscent along both sides, or indehiscent; (2) a crop species in the family Fabaceae; (3) a plant belonging to the Leguminosae (Fabaceae family).
  • lemma: the lower of 2 bracts enclosing a grass flower.
  • lenticel: a loosely packed mass of cells in the bark of a woody plant (used for gas exchange), visible on the surface as a raised powdery spot.
  • lepidote: covered with small scurfy scales.
  • liane: a woody climbing or twining plant.
  • lignotuber: a woody swelling of the stem below or just above the ground; contains adventitious buds from which new shoots can develop, e.g. after fire.
  • ligulate: (1) bearing a ligule; (2) strap-shaped.
  • ligule: (1) small membranous appendage on the top of the sheath of grass leaves; (2) a minute adaxial appendage near the base of a leaf, e.g. in Selaginella; (3) extended, strap-like corolla of some daisy florets.
  • linear: very narrow in relation to its length, with the sides mostly parallel.
  • lithophytic: growing on rocks; epilithic.
  • lobe: part of a leaf (or other organ), often rounded, formed by incisions to about halfway to the midrib.*
  • loculicidal: of a fruit, when it dehisces through the centres of loculi; cf. septicidal.
  • loculus: a chamber or cavity, e.g., within an ovary.*
  • lomentum: a pod-like indehiscent fruit that develops constrictions between the segments and at maturity breaks into one-seeded segments.*
  • lunate: crescent-shaped.
  • lyrate: lyre-shaped; deeply lobed, with a large terminal lobe and smaller lateral ones.

M

  • Macaronesia: a biogeographic area encompassing the islands off the coast of NW Africa and Europe, including the Azores, Canaries, Cape Verde Islands and Madeira.
  • Malaysia: Malay peninsula and North Borneo.
  • Malesia: a biogeographic region comprising Malaysia, Indonesia, New Guinea, and the Philippines.
  • mallee: growth habit in which several woody stems arise separately from a lignotuber; a plant with such a growth habit; vegetation characterized by such plants.
  • mangrove: a shrub or small tree growing in salt or brackish water, usually characterized by pneumatophores.
  • margin: the edge, as in the edge of a leaf blade.
  • marginal: occurring at or very close to the margin.
  • marsh: a waterlogged area; swamp.
  • mealy: covered with coarse, floury powder, sometimes due to collapsed hairs.
  • megaspore: the larger of 2 kinds of spores produced by a heterosporous plant giving rise to the female gametophyte; cf. microspore.
  • membranous: thin, translucent and flexible, seldom green.
  • mericarp: one segment of a fruit (a schizocarp) that splits at maturity into units derived from the individual carpels, or a carpel, usually 1-seeded, released by the break-up at maturity of a fruit formed from 2 or more joined carpels.
  • meristem: a group of actively dividing tissues.
  • mesic: moist, avoiding both extremes of drought and wet; pertaining to conditions of moderate moisture or water supply; applied to organisms (vegetation) occupying moist habitats.
  • mesocarp: the fleshy portion of the wall of a succulent fruit inside the skin and outside the stony layer (if any), surrounding the seed(s); sarcocarp.
  • mesomorphic: soft and with little fibrous tissue, but not succulent.
  • mesophyll: photosynthetic tissue of a leaf; of vegetation, characteristic of moist habitats and with soft, fairly large leaves predominating.
  • mesophyte: a plant thriving under intermediate environmental conditions of moderate moisture and temperature, without major seasonal fluctuations.
  • Micronesia: a federation of island states in the western Pacific Ocean, comprising the Mariana, Marshall, Caroline, and Gilbert Islands groups.
  • microspore: the smaller of 2 kinds of spores produced by a heterosporous plant; cf. megaspore.
  • midrib: the central, and usually most prominent, vein of a leaf or leaf-like organ; midvein.
  • midvein: see midrib.
  • moniliform: resembling a string of beads.
  • monochasium: a cymose inflorescence with the branches arising singly; cf. dichasium.
  • monocots: abbreviation of monocotyledons.
  • monocotyledon: a flowering plant whose embryo has one cotyledon (seed leaf); cf. dicotyledon.
  • monoecious: of vascular plants, where the male and female reproductive structures are in separate flowers but on the same plant; of inflorescence, including unisexual flowers of both sexes; cf. dioecious.
  • monograph: of a group of plants, a comprehensive treatise presenting an analysis and synthesis of taxonomic knowledge of that taxon; i.e. the fullest account possible (at the time) of a family, tribe or genus. It is generally worldwide in scope and evaluates all taxonomic treatments of that taxon including studies of its evolutionary relationships with other related taxa, and cytological, genetic, morphological, palaeobotanical and ecological studies. The term is often incorrectly applied to any systematic work devoted to a single taxon. cf. revision.
  • monotypic: containing only one taxon of the next lower rank, e.g. a family with only one genus, or a genus that includes only a single species.
  • morphology: the shape or form of an organism or part thereof.
  • mucro: a sharp, short point.
  • mucronate: terminating in a mucro.
  • multiple fruit: a cluster of fruits produced from more than one flower and appearing as a single fruit, often on a swollen axis, as in Moraceae; cf. aggregate fruit.
  • muricate: covered with short hard protuberances.
  • mutation: an abrupt and inexplicable variation from the norm, such as the doubleness in flowers, changes in colour, or habit of growth.

N

  • native: naturally occurring in an area, but not necessarily confined to it; cf. endemic.
  • natural hybrid: a hybrid taxon produced by chance in the wild.
  • naturalised: describing a plant, introduced from another region, that grows and reproduces readily in competition with the natural flora.
  • nectar: a (usually sweet) fluid produced by the flowers of many plants, collected by bees and other insects.
  • nectary (adjective nectariferous): a specialized gland that secretes nectar.
  • nerve: see vein.
  • New World: the Americas.
  • node: the part of a stem where leaves or branches arise.
  • nomen conservandum: (Latin) a name which although, contrary to the rules of nomenclature (usually a later synonym), must be adopted.
  • nomen illegitimum: (Latin) a name that is superfluous at its time of publication either because the taxon to which it was applied already has a name, or because the name has already been applied to another plant.
  • nomen nudum: (Latin) a name not published in accordance with the International Code of Botanical Nomenclature, usually without a diagnosis or description of the entity to which it applies, and without reference to either; such a name should not be used.
  • nomenclature: the naming of things; often restricted to the correct use of scientific names in taxonomy; a system that sets out provisions for the formation and use of names.
  • noxious: of plants, containing harmful or unwholesome qualities. Applied in conjunction with 'weed' to specifically describe a plant which legislation deems harmful to the environment. Each state and territory in Australia has specific legislation governing noxious weeds.
  • nut: a hard, dry, indehiscent fruit, containing only one seed.
  • nutlet: a small nut, one of the lobes or sections of the mature ovary of some members of the Boraginaceae, Verbenaceae, and Lamiaceae.

O

  • ob-: inversely; usually same shape as suffix but attached by the narrower end, e.g. obcordate, oblanceolate, obovate.
  • obcordate: of a leaf blade, broad and notched at the tip; heart shaped but attached at the pointed end.
  • oblanceolate: a 2-dimensional shape, lanceolate but broadest in the upper third; cf. lanceolate.
  • obligate: of parasites, unable to survive without the host; cf. facultative.
  • oblique: slanting; of a leaf, larger on one side of the midrib than the other, i.e. asymmetrical.
  • oblong: length a few times greater than width, with sides almost parallel and ends rounded.
  • obovate: of a leaf, a 2-dimensional shape of which the length is about 1.5 times the width, and widest above the centre.
  • obtuse: blunt or rounded at the tip or apex; converging edges making an angle of more than 90°; cf. acute.
  • Oceania: the islands of the Pacific (sometimes including Australia).
  • ocrea (ochrea): a sheath, formed from two stipules, encircling the node in Polygonaceae.
  • Old World: the world known before the discovery of America; essentially Europe and Asia.
  • ontogeny: the sequence of developmental stages through which an organism passes.
  • operculum (calyptra): a lid or cover that becomes detached at maturity, e.g. in Eucalyptus, a cap covering the bud and formed by the fusion or cohesion of perianth parts.
  • opposite: (as adjective) leaves or flowers borne at the same level but on opposite sides of the axis; or (as verb) when something occurs on the same radius as something else, e.g. anthers opposite sepals; cf. alternate.
  • orbicular: flat and more or less circular.
  • order: a group of one or more families sharing common features and/or ancestry.
  • ortet: the original single parent plant from which a clone ultimately derives.
  • orthotropous: when an ovule is erect, with the micropyle directed away from the placenta; atropous; cf. amphitropous, anatropous, campylotropous.
  • oval: see elliptical.
  • ovary: the basal portion of a carpel or group of fused carpels, enclosing the ovule(s).
  • ovate: shaped like a section through the long-axis of an egg and attached by the wider end.
  • ovoid: egg-shaped, with wider portion at base; 3-dimensional object, ovate in all sections through long-axis.
  • ovule: loosely, the seed before fertilization; a structure in a seed plant within which one or more megaspores are formed (after fertilization it develops into a seed).

P

  • palea: the upper of 2 bracts enclosing a grass flower.
  • palmate: (1) a compound leaf divided into several leaflets arising from the same point at the top of the petiole; (2) of veins in a simple leaf when they arise in a similar fashion.
  • palmatifid: deeply divided into several lobes arising from more or less the same level.
  • palmatisect: intermediate between palmate and palmatifid, i.e. the segments are not fully separated at the base; often more or less digitate.
  • panicle (adjective paniculate): a compound raceme; an indeterminate inflorescence in which the flowers are borne on branches of the main axis or on further branches of these.
  • papilionate: butterfly-like; with a corolla like that of a pea.
  • papilla (plural papillae, adjective papillose): a small, elongated protuberance on the surface of an organ, usually an extension of one epidermal cell.
  • pappus: in daisy florets, a tuft or ring of hairs or scales borne above the ovary and outside the corolla (representing the missing calyx); a tuft of hairs on a fruit.
  • parasite: an organism living on or in a different organism, from which it derives nourishment; cf. saprophyte, epiphyte.
  • parietal: attached to the marginal walls of a structure, e.g. ovules attached to placentas on the wall of the ovary.
  • paripinnate: having an even number of pinnae (terminated by a pair of pinnae); cf. imparipinnate.
  • patent: of plants, spreading.
  • pectinate: pinnately divided with narrow segments closely set like the teeth of a comb.
  • pedate: with a terminal lobe or leaflet, and on either side of it an axis curving outwards and backwards, bearing lobe or leaflets on the outer side of the curve.*
  • pedicel (adjective pedicellate): the stalk of a flower.
  • peduncle (adjective pedunculate): the stalk of an inflorescence.
  • peltate: shield-like; with stalk attached to the lower surface and not to the margin.
  • pendulous: hanging, e.g. an ovule attached to a placenta on the top of the ovary; cf. suspended.
  • penicillate: tufted like an artist's brush; with long hairs towards one end.
  • penninervation (penninerved): with pinnately arranged veins.
  • pepo: type of berry formed from an inferior ovary and containing many seeds, usually large with a tough outer skin, e.g., pumpkin, cucumber.
  • perennating: of an organ that survives vegetatively from season to season. A period of reduced activity between seasons is usual.
  • perennial: a plant whose life span extends over several years.
  • perfect: of a flower, when bisexual.
  • perfoliate: with its base wrapped around the stem (so that the stem appears to pass through it), e.g. of leaves and bracts.
  • perianth: the collective terms for the calyx and corolla of a flower (generally used when the two are similar).
  • pericarp: the wall of a fruit, developed from the ovary wall.
  • perigynous: borne around the ovary, i.e. of perianth segments and stamens arising from a cup-like or tubular extension of receptacle (free from the ovary but extending above its base); cf. epigynous, hypogynous.
  • persistent: remaining attached to the plant beyond the usual time of falling, e.g. sepals not falling after flowering; cf. deciduous, caducous.
  • perule: (1) the scaly covering of a leaf or flower bud; (2) in camellias the final bracts and sepals become indistinguishable and are called perules; (3) a kind of sac formed by the adherent bases of the two lateral sepals in certain orchids.
  • petal: in a flower, one of the segments or divisions of the inner whorl of non-fertile parts surrounding the fertile organs, usually soft and conspicuously coloured; cf. sepal.
  • petaloid: like a petal; soft in texture and coloured conspicuously.
  • petiolate: subtended by a petiole.
  • petiole: the stalk of a leaf.
  • petiolule: the stalk of a leaflet.
  • phanerogam: gymnosperms and angiosperms; plants producing stamens and gynoecia; literally plants with conspicuous sexual reproductive organs; cf. cryptogams.
  • photosynthesis: the process by which sugars are made from carbon dioxide and water in cells containing chloroplasts; the chemical energy required from solar energy in the presence of the pigment chlorophyll.
  • phyllode (adjective phyllodineous): a leaf with the blade much reduced or absent, and in which the petiole and or rachis perform the functions of the whole leaf; e.g. many acacias; cf. cladode.
  • pilose: covered with soft, weak, thin and clearly separated hairs, which are usually defined as long and sometimes ascending.
  • pinna (plural pinnae): a primary segment of a compound leaf.
  • pinnate: a compound leaf with leaflets arranged on each side of a common petiole or axis; also applied to how the lateral veins are arranged in relation to the main vein.
  • pinnatifid: pinnately lobed.
  • pinnatisect: pinnately divided almost to midrib but segments still confluent.
  • pinnule: ultimate free division (or leaflet) of a compound leaf.
  • pistil: (1) a single carpel when the carpels are free; (2) a group of carpels when the carpels are united by the fusion of their walls.
  • pith: the central region of a stem, inside the vascular cylinder; the spongy parenchymatous central tissue in some stems and roots.
  • placenta: the tissue within an ovary to which the ovules are attached.
  • placentation: the arrangement of ovules inside ovary; e.g. axile, free-central, parietal, marginal, basal, or apical.
  • Plant Breeders Rights (PBR): these rights, governed by Plant Breeder's Rights Acts give the plant breeder legal protection over the propagation of a cultivar, and the exclusive rights to produce and to sell it, including the right to license others to produce and sell plants and reproductive material of a registered, deliberately bred variety. Cf. UPOV.
  • Plant Variety Rights (PVR): governed by the Plant Variety Rights the registration of new varieties is now governed by Plant Breeders Rights.
  • plicate: pleated; folded back and forth longitudinally like a fan.
  • plumose: like a feather; with fine hairs branching from a main axis.
  • plumule: the part of an embryo that gives rise to the shoot system of a plant; cf. radicle.
  • pneumatophore: a vertical, aerial (at low tide) appendage to the roots of some plants, through which gases are exchanged; e.g. on mangroves.
  • pod: (1) a legume, the fruit of a leguminous plant, a dry fruit of a single carpel, splitting along two sutures; (2) siliqua and silicula, the fruit of Brassicaceae, a dry fruit composed of two carpels separated by a partition.
  • pollen: powdery mass shed from anthers (of angiosperms) or microsporangia (of gymnosperms); the microspores of seed plants; pollen-grains.
  • pollen-mass: pollen-grains cohering by a waxy texture or fine threads into a single body; pollinium; e.g. in orchids.
  • pollination: the transfer of pollen from the male organ (anther) to the receptive region of a female organ (stigma).
  • pollinium: see pollen-mass.
  • polygamodioecious: having bisexual and male flowers on some plants and bisexual and female flowers on others; cf. androdioecious, andromonoecious, dioecious, monoecious, polygamomonoecious, polygamous.
  • polygamomonoecious: having male, female and bisexual flowers on the same plant; cf. androdioecious, andromonoecious, polygamodioecious, polygamous.
  • polygamous: having bisexual and unisexual flowers on the same plant.
  • polymorphic: of several different kinds (in respect to shape and/or size).
  • polyploid: with more than two of the basic sets of chromosomes in the nucleus; any individual (or a cell) containing three or more complete sets of chromosomes. Various combinations of words or numbers with '-ploid' indicate the number of haploid sets of chromosomes; e.g. triploid = 3 sets, tetraploid = 4 sets, pentaploid = 5 sets, hexaploid = 6 sets, and so on.
  • pome: a fruit that has developed partly from the ovary wall but mostly from the floral tube, e.g., apple.
  • population: (1) all individuals of one or more species within a prescribed area; (2) a group of organisms of one species, occupying a defined area and usually isolated to some degree from other similar groups; (3) in statistics, the whole group of items or individuals under investigation.
  • posterior: the side nearest the axis; cf. anterior.
  • prickle (adjective: prickly): hard, pointed outgrowth from the surface of a plant (involving several layers of cells but not containing a vein); sharp outgrowth from the bark, detachable without tearing wood; cf. thorn.
  • prophyll: a leaf formed at the base of a shoot, usually smaller than those formed later.
  • pro parte: (Latin) in part; in nomenclature, to denote that the preceding taxon includes more than one currently recognized entity, and that only one of those entities is being considered.
  • procumbent: spreading along the ground but not rooting at the nodes: not as close to ground as prostrate.
  • propagules: a structure capable of producing a new plant; includes seeds, spores, bulbils, etc.
  • prostrate: lying flat on the ground.
  • protandrous: male sex organs maturing before the female ones, e.g. a flower shedding pollen before the stigma is receptive; cf. protogynous.
  • prothallus: a gametophyte body, usually flattened and delicate; e.g. in ferns and fern allies.
  • protogynous: female sex organs maturing before the male ones, e.g. a flower shedding pollen after the stigma has ceased to be receptive; cf. protandrous.
  • proximal: near the point of origin or attachment; cf. distal.
  • pruinose: covered with a powdery, waxy material; with a bloom.
  • pseudo: false; apparently but not genuine; e.g. pseudo-bulb = a thickened, bulb-like internode in orchids, or a corm.
  • puberulous (puberulent): covered with minute soft erect hairs.
  • pubescent: downy; covered with short, soft, erect hairs.
  • pulvinus: a swelling at the base of a leaf or leaflet stalk, often glandular or responsive to touch.
  • punctate: marked with dots.
  • pungent: having a sharp hard point.
  • pyramidal: of a plant's form, tetrahedral, pyramid-shaped.
  • pyriform: pear-shaped.

Q

R

  • raceme (adjective racemose): an indeterminate inflorescence in which the main axis produces a series of flowers on lateral stalks, the oldest at the base and the youngest at the top; cf. spike.
  • rachilla (rhachilla): the axis of a grass spikelet, above the glumes.
  • rachis (plural rachises; rhachis): the axis of an inflorescence or a pinnate leaf; e.g. ferns; secondary rachis is the axis of a pinna in a bipinnate leaf distal to and including the lowermost pedicel attachment
  • radial: with structures radiating from a central point as spokes on a wheel, e.g., the lateral spines of a cactus.
  • radiate: of daisies, of a capitulum, with ray florets surrounding disc florets.
  • radical: springing from the root; clustered at base of stem.
  • radicle: the part of an embryo giving rise to the shoot system of a plant; cf. plumule.
  • rainforest: a forest dominated by broad-leaved trees with dense crowns that form a continuous layer (canopy) and with one or more of the following growth forms: epiphytes, lianas, treeferns, palms; eucalypts absent or are present only as isolated emergen, e.g. in Victoria, mesic vegetation is dominated by trees other than eucalypts, often with lianas and epiphytes.
  • ramet: an individual member of a clone.
  • ray: (1) zygomorphic (ligulate) flowers in a radiate flowerhead, i.e. ray-florets/flowers, e.g. Asteraceae; (2) each of the branches of an umbel.
  • receptacle: the axis of a flower, i.e. floral axis; torus; e.g. in Asteraceae, the floral base or common receptacle is the expanded summit of the peduncle on which the flowers are inserted.
  • recurved: bent or curved backwards or downwards.
  • reflexed: bent sharply back or down.
  • registered name: a cultivar name accepted by the relevant International Registration Authority.
  • registered trade mark: a trade mark formally accepted by a statutory trade-mark authority and distinguished by the international ® sign.
  • registration: (1) the act of recording a new cultivar name with an International Cultivar Registration Authority; (2) recording a new cultivar name with a statutory authority like the Plant Breeder’s Rights Office (3) recording a trade mark with a trade marks office cf. registered trade mark.
  • regular: see actinomorphic.
  • reniform: kidney-shaped.
  • reticulate: forming a network (or reticulum), e.g. veins that join one another at more than one point.
  • retrorse: directed backwards or downwards; cf. antrorse.
  • retuse: with a blunt (obtuse) and slightly notched apex.
  • revision: an account of a particular plant group, like an abbreviated or simplified monograph. Sometimes confined to the plants of a particular region. Similar to a monograph in clearly distinguishing the taxa and providing a means for their identification; cf monograph.
  • revolute: rolled under (downwards or backwards), e.g. when the edges of leaves are rolled under towards the midrib; cf. involute.
  • rhachis: see rachis.
  • rhizome: a perennial underground stem usually growing horizontally.
  • rhombic: like a rhombus, i.e. an oblique figure with four equal sides; cf. trapeziform, trullate.
  • rhomboid: a 4-sided figure with opposite sides parallel but with adjacent sides an unequal length (i.e. like an oblique rectangle); see also rhombic.
  • rhomboidal: a shape, e.g. of a leaf, that is roughly diamond-shaped with length = width.
  • root: a unit of a plant's axial system which is usually underground, does not bear leaves, tends to grow downwards, and is typically derived from the radicle of the embryo.
  • root hairs: outgrowths of the outermost layer of cells just behind the root tips, functioning as water-absorbing organs.
  • rootstock: short, erect, swollen structure at junction of a plant's root and shoot systems, e.g. a corm. Also used to describe (1) a part of a budded or grafted plant which supplies the roots, also called a rootstock, or plants grown specifically to produce these; (2) plants or seeds with some specific attribute e.g. virus-free plants.
  • rosette: when parts are not whorled or opposite but appear so, due to the contractions of internodes, e.g. the petals in a double rose or a basal cluster of leaves (usually close to the ground) in some plants.
  • rostrate: with a beak.
  • rotate: circular and flattened; e.g. a corolla with a very short tube and spreading lobes (e.g. some Solanaceae).
  • rudimentary: poorly developed and not functional; cf. vestigial.
  • rugose: wrinkled.
  • rugulose: finely wrinkled.
  • runcinate: sharply pinnatifid or cleft, the segments directed downward
  • runners: see stolon.
  • rush: a plant belonging to the family Juncaceae or, more loosely, applied to various monocotyledons.

S

  • saccate: pouched.
  • sagittate: shaped like the head of an arrow; narrow and pointed but gradually enlarged at base into two straight lobes directed downwards; may refer only to the base of a leaf with such lobes; cf. hastate.
  • samara: a dry, indehiscent fruit with its wall expanded into a wing.*
  • samphire: (in Australia) any plant of the tribe Salicorniae (chenopodiaceae), e.g. Sarcocornia, Halosarcia, Sclerostegia; or a community dominated by one or more of these species.
  • saprophyte (adjective saprophytic): an organism deriving its nourishment from decaying organic matter and usually lacking chlorophyll; cf. parasite, epiphyte.
  • scabrid (scabrous): rough to the touch with short hard emergences or hairs. *
  • scale: (1) a reduced or rudimentary leaf, e.g. around a dormant bud; (2) a thin flap of tissue.
  • scape (adjective scapose): a stem-like flowering stalk of a plant with radical leaves.
  • scarious: dry and membranous.
  • schizocarp: a dry fruit formed from more than one carpel but breaking apart into individual carpels (mericarps) when ripe.
  • scion: the aerial part of a graft combination, induced by various means to unite with a compatible understock/roostock.
  • sclerophyll (adjective sclerophyllous): a plant with hard, stiff leaves; leaves stiffened with thick-walled cells.
  • scorpioid: of a cymose inflorescence, when it branches alternately on one side and then the other; cf. helicoid.
  • scrub: dense vegetation dominated by shrubs.
  • section (sectio): the category of supplementary taxa intermediate in rank between subgenus and series. It is a singular noun always written with a capital initial letter, in combination with the generic name.
  • secund: with all the parts grouped on one side or turned to one side (applied especially to inflorescences.
  • sedge: a plant belonging to the family Cyperaceae.
  • seed: a ripened ovule, consisting of a protective coat enclosing an embryo and food reserves; a propagating organ formed in the sexual reproductive cycle of gymnosperms and angiosperms (together, the seed plants).
  • segment: part or subdivision of an organ, e.g. a petal is a segment of the corolla. A term sometimes used when the sepals and petals are indistinguishable.
  • self-pollination: also called selfing, the acceptance by stigmas of pollen from the same flower or from flowers on the same plant, which means they are self-compatible.
  • sensu: in the sense of.
  • sensu lato: of a plant name, in its broadest sense.
  • sensu stricto: of a plant name, in its narrowest sense.
  • sepal: in a flower, one of the segments or divisions of the outer whorl of non-fertile parts surrounding the fertile organs, usually green; cf. petal.
  • septicidal: of a fruit, when it dehisces along the partitions between loculi; cf loculicidal.
  • septum (plural septa): a partition, e.g. the membranous wall separating the two valves of the pod of Brassicaceae.
  • sericeous: silky with dense appressed hairs.
  • series: the category of supplementary taxa intermediate in rank between section and species. It is a plural adjective; e.g. Primula subgenus Primula sect. Primula series Acaules.
  • serrate: toothed with asymmetrical teeth pointing forward; like the cutting edge of a saw.
  • serrulate: finely serrate.
  • sessile: without a stalk, e.g. of a stigma, when the style is absent.
  • seta (adjectives setose, setaceous): a bristle or stiff hair (in Bryophytes, the stalk of the sporophyte); a terminal seta is an appendage to the tip of an organ, e.g. the primary rachis of a bipinnate leaf in Acacia.
  • sheath: a tubular or rolled part of an organ, e.g. the lower part of the leaf in most grasses.
  • shoot: usually the aerial part of a plant; a stem including its dependent parts, leaves flowers etc.
  • shrub: a woody perennial plant without a single main trunk, branching freely, and smaller than a tree.
  • sigmoid: shaped like the letter 'S'.
  • silicula: a stout siliqua (not more than twice as long as wide).
  • siliqua: a dry, dehiscent fruit (more than twice as long as wide) formed from a superior ovary of two carpels, with two parietal placentas and divided into two loculi by a 'false' septum.
  • silky: densely covered with fine soft straight appressed hairs, with a lustrous sheen and satiny to the touch..
  • silviculture: the science of forestry and the cultivation of woodlands for commercial purposes and wildlife conservation.
  • simple: undivided, e.g. a leaf not divided into leaflets (note, however, that a simple leaf may be entire, toothed or lobed) or an unbranched hair or inflorescence.
  • sinuate: with deep, wave-like depressions along the margins, but more or less flat; cf. undulate.
  • sinus: a notch or depression between two lobes or teeth in the margin of an organ.
  • solitary: single, of flowers that grow one plant per year, one in each axil, or widely separated on the plant; not grouped in an inflorescence.
  • spadix: a spicate inflorescence with a stout, often succulent axis.
  • spathe: a large bract ensheathing an inflorescence.
  • spathulate (spatulate): spoon-shaped; broad at the tip with a narrowed projection extending to the base.
  • species: a group, or populations of individuals, sharing common features and/or ancestry, generally the smallest group that can be readily and consistently recognized; often, a group of individuals capable of interbreeding and producing fertile offspring. The basic unit of classification, the category of taxa of the lowest principal rank in the nomenclatural hierarchy.
  • specific epithet: follows the name of the genus, and is the second word of a botanical binomial. The generic name and specific epithet together constitute the name of a species; i.e. the specific epithet is not the species name.
  • spike (adjective spicate): an unbranched, indeterminate inflorescence in which the flowers are without stalks; cf. raceme.
  • spikelet: a unit of the inflorescence especially in grasses, sedges and some other monocotyledons, consisting of one to many flowers and associated bracts (glumes).
  • spine (adjective spinose): a stiff, sharp structure, formed by the modification of a plant organ that contains vascular tissue; e.g. a lateral branch or a stipule; includes thorns.
  • spinescent: ending in a spine; modified to form a spine.
  • spiral: of arrangement, when plant parts are arranged in a succession of curves like the thread of a screw, or coiled in a cylindrical or conical manner.
  • sporangium (sporangia): a structure in which spores are formed.
  • spore: in non-flowering plants only a simple propagule, produced either sexually or asexually, and consisting of one or a few cells.
  • sporocarp: a fruiting body containing spores.
  • sporophyte: a plant, or phase of a life cycle, that bears the spores; cf. gametophyte.
  • sport: a naturally occurring variant of a species, not usually present in a population or group of plants; a plant that has spontaneously mutated so that it differs from its parent plant.
  • spreading: extending horizontally, e.g. branches; standing out at right angles to axis, e.g. leaves or hairs.
  • spur: (1) a short shoot; (2) a conical or tubular outgrowth from the base of a perianth segment, often containing nectar.
  • stalk: the supporting structure of an organ, usually narrower in diameter than the organ.
  • stamen (adjective staminate): male organ of a flower, consisting (usually) of a stalk (filament) and a pollen-bearing portion (anther).
  • staminode: a sterile stamen, often rudimentary.
  • standard: the large posterior petal of pea-flowers.
  • standard specimen: a representative specimen of a cultivar (or other taxon), one that demonstrates how the name of that taxon should be used.
  • stellate: star-shaped, e.g. a type of hair.
  • stem: the plant axis, either aerial or subterranean, which bears nodes, leaves, branches and flowers.
  • stem-clasping: see amplexicaul.*
  • sterile: infertile, e.g. a stamen that does not bear pollen, or a flower that does not bear seed.
  • stigma: the pollen-receptive surface of a carpel or group of fused carpels, usually sticky; usually a point or small head at the summit of the style.
  • stipe: in ferns, the stalk of a frond; generally a small stalk.
  • stipella (stipel; plural stipellae): one of two small secondary stipules at the base of leaflets in some species. *
  • stipitate: stalked; borne on a stipe; of an ovary, borne on a gynophore
  • stipulate: bearing stipules.
  • stipule: small appendage at the bases of leaves in many dicotyledons.
  • stolon: slender, prostrate or trailing stem, producing roots and sometimes erect shoots at its nodes.
  • stoloniferous: having stolons.*
  • stoma (plural stomata): a pore; small hole in the surface of a leaf (or other aerial organ) allowing the exchange of gases between tissues and the atmosphere.
  • striate: striped with parallel, longitudinal lines or ridges.
  • strigose: covered with appressed, rigid, bristle-like, straight hairs; the appressed equivalent of hispid. *
  • strobilis (plural strobili): a cone-like structure consisting of sporophylls borne close together on an axis, e.g. in some club-mosses.
  • style: an elongated part of a carpel, or group of fused carpels, between the ovary and the stigma.*
  • subgenus: the category of supplementary taxa intermediate between genus and section. It is a singular noun, always has a capital initial letter and is used in combination with the generic name; e.g. Primula subgenus Primula.
  • subshrub: undershrub; small shrub which may have partially herbaceous stems, but generally a woody plant less than 1 m high.
  • subspecies: a grouping within a species, usually used for geographically isolated and morphologically distinct entities. Its taxonomic rank occurs between species and variety.
  • subtend: to stand beneath or close to, as in a bract at the base of a flower.
  • subulate: narrow and tapering gradually to a fine point.
  • succulent: juicy, fleshy; a plant with a fleshy habit.
  • sucker: a shoot of more or less subterranean origin; an erect shoot originating from a bud on a root or a rhizome, sometimes at some distance from the stem of the plant.*
  • sulcate: furrowed; grooved.
  • superficial: on the surface.
  • superior: of an ovary, borne above the level of attachment of the other floral parts, or above the base of a floral tube (i.e. one that is free from the ovary and bears the perianth and stamens); cf. inferior, half-inferior.
  • suspended: of an ovule, when attached slightly below the summit of the ovary; cf. pendulous.
  • sward: extensive, more or less even cover of a surface, e.g. a lawn grass; cf. tussock.
  • sympatric: with more or less similar or overlapping ranges of distribution.
  • syn- (sym-): with, together.
  • synangium: a fused aggregate of sporangia.
  • syncarpous: of a gynoecium, made up of united carpels.
  • synonym: outdated name or 'alternative' name for the same taxon.

T

  • taproot: the main, descending root of a plant with a single dominant root axis.
  • taxon (plural taxa): a group or category in a system of classification, derived from the Greek prefixes taxo-, taxis- meaning arrangement.
  • taxonomy: the study of the principles and practice of classification.
  • tendril: a slender organ (modified e.g. from stem, leaf, leaflet or stipule) used by climbing plants to cling to an object.
  • tepal: perianth segment, either sepal or petal; usually used when all perianth segments are similar in appearance; cf. petal.
  • terete: circular in cross-section; more or less cylindrical.
  • terminal: situated at the tip or apex.
  • ternate: in groups of three; of leaves, arranged in whorls of three; of a single leaf, with the leaflets arranged in groups of three.
  • terrestrial: generally denotes of or on the ground; of habitat, on land as opposed to in water (aquatic) or on rocks (lithophytic), or other plants (epiphytic), etc.
  • testa: seed coat.
  • tetrad: a group of four; usually means four pollen grains remaining fused together a maturity, e.g. in the Epacridaceae.
  • thorn: a sharp, stiff point, usually a modified stem, that cannot be detached without tearing the subtending tissue; a spine; cf. prickle.
  • throat: the opening of a corolla or perianth.
  • thyrse: a branched inflorescence in which the main axis is indeterminate (racemose) and the lateral branches determinate (cymose).
  • tomentum (adjective tomentose): a dense covering of short, matted hairs. Tomentose is often used as a general term for bearing an indumentum, but this is not a recommended use.
  • toothed: with a more or less regularly incised margin.
  • torus: see receptacle.
  • trademark (trade mark): a distinctive word, picture, symbol, smell or other device or any combination or multiples of these. It must not be descriptive of the goods or services, nor can it be geographical nor a surname. Used to distinguish one trader from another, compared with PBR which protect the commercial name of a particular plant variety.
  • trapeziform: (1) like a trapezium (a 4-sided figure with two parallel sides of unequal length); (2) like a trapezoid (a 4-sided figure with neither pair of sides equal); sometimes used erroneously as a synonym for rhombic.
  • tree: a woody plant, usually with a single distinct trunk and generally more than 5 m tall.
  • triad: a group of three.
  • triangular: planar and with 3 sides.
  • tribe: a taxonomic grouping, in rank between genus and species.
  • trichome: in non-filamentous plants, any hair-like outgrowth from epidermis, e.g. a hair or bristle; sometimes restricted to unbranched epidermal outgrowths.
  • trifoliolate: a compound leaf of three leaflets, e.g. a clover leaf.
  • trigonous: triangular in cross-section and obtusely angled; cf. triquetus.
  • triquetrous: more or less triangular in cross-section, but acutely angled (with 3 distinct longitudinal ridges); cf. trigonus.
  • trivial name: the second word in the two-part scientific name of an organism; cf. specific epithet.
  • trullate: ovate but angled; like a brick-layers trowel; inverse kite-shaped; cf. rhombic.
  • truncate: cut off squarely; with an abruptly transverse end.
  • trunk: the upright large main stem of a tree.
  • truss: a compact cluster of flowers or fruits arising from one centre; e.g. evident in many rhododendrons.
  • tuber: an underground storage organ formed by the swelling of an underground stem which produces buds and stores food, forming a seasonal perennating organ, e.g. potato; cf. tuberoid.
  • tubercle: a small wart-like outgrowth.
  • tuberculate: covered in tubercles; warty.
  • tuberoid: an underground storage organ formed by the swelling of a root; occurs in many orchids.
  • tuberous: resembling a tuber; producing tubers.
  • tubular: with the form of a tube or cylinder.
  • tunic: outer covering of some bulbs and corms.
  • turbinate: top-shaped.
  • turgid: swollen with liquid; firm; cf. flaccid.
  • tussock: a dense tuft of vegetation, usually well separated from neighbouring tussocks, e.g. some grasses; cf. sward.
  • type: an item (usually a herbarium specimen) to which the name of a taxon is permanently attached, i.e. a designated representative of a plant name. Important in determining the priority of names available for a particular taxon.
  • type genus: in nomenclature, the genus from which the family is based.
  • typography: the presentation of printed matter, covering issues such as type styles (e.g. italic or roman type), underlining, emboldening and letter spacing.

U

  • umbel (adjective umbellate): a racemose inflorescence in which all the individual flower stalks arise in a cluster at the top of the peduncle and are of about equal length; in a simple umbel, each stalk is unbranched and bears only one flower; a cymose umbel is an apparent umbel but its flowers open centrifugally.
  • umbonate: with a conical projection arising from a flatter surface.
  • uncinate: with a hook at the apex.
  • undershrub: a low shrub, often with flowering branches that die off in winter; cf. subshrub.
  • undulate: wavy and not flat; cf. sinuate.
  • unilocular: having one loculus or chamber, e.g., the ovary in the families Proteaceae and Fabaceae.
  • unisexual: of one sex; bearing only male or only female reproductive organs.
  • urceolate: urn-shaped.
  • utricle: a small bladder; a membranous bladder-like sac enclosing an ovary or fruit; in sedges a fruit in which the pericarp is larger than, and loosely encloses, the seed.

V

  • valvate: of sepals and petals in bud, which meet edge to edge but do not overlap.
  • valve: a portion of an organ that fragments or splits open, e.g. the teeth-like portions of a pericarp in a split (dehisced) capsule.
  • variant: a plant or group of plants showing some measure of difference from the characteristics associated with a particular taxon.
  • varietas (variety in common usage, abbreviated as var.): (Latin) subdivision of a species, between the categories of subspecies and form.
  • variegated: irregularly marked with blotches or patches of another colour.
  • vein: a strand of vascular tissue; nerve.
  • veinlet: a small vein; the ultimate (visible) division of a vein.
  • velvety: densely covered with fine, short, soft, erect hairs.
  • venation: the arrangement of veins in a leaf.
  • ventral: the front; in particular, towards the axis in a lateral organ or towards substratum in prostrate plant; cf. dorsal.
  • vernation: the arrangement of unexpanded leaves in a bud; the order of unfolding of leaves from a bud.
  • verrucose: with warts.
  • versatile: of anthers, swinging freely about the point of attachment to the filament.
  • verticillate: arranged in one or more whorls.
  • vescicular: of hairs, bladder-like; vesciculous, bearing such hairs.
  • vessel: a capillary tube formed from a series of open-ended cells in the water-conducting tissue of a plant.
  • vestigia: reduced in form and function from the normal or ancestral condition.
  • villous: covered with long, soft, weak hairs, the covering somewhat dense.
  • viscid: sticky; coated with a thick, syrupy secretion.
  • viviparous: (1) seeds or fruits which germinate before being shed from the parent plant, (2) the development of plantlets on non-floral organs e.g. leaves.

W

  • warty: a surface covered with small round protuberances, especially in fruit, leaves, twigs and bark, see tuberculate.
  • watershoot: an erect strong-growing or epicormic shoot developing from near the base of a shrub or tree, but distinct from a sucker.
  • weed: loosely defined as a plant growing where it is not wanted; commonly associated with disrupted habitats; (1) agricultural weed: a plant which taints produce or pollutes crops; (2) environmental weed: naturalised, exotic or ecologically 'out-of-balance' indigenous species outside the agricultural or garden context which, as a result of invasion, adversely affects the survival or regeneration of indigenous species in natural or partly-natural vegetation communities (Carr, G.W., in Foreman & Walsh, 1993).
  • wild: originating from a known wild habitat.
  • whorl: a ring of organs borne at the same level on an axis, e.g. leaves, bracts or floral parts.
  • wing: (1) a membranous expansion of a fruit or seed which aids in dispersal, e.g. on pine seeds; (2) a thin flange of tissue extending beyond the normal outline of a structure, e.g. on the column of some orchids, on stems, on petioles; (3) a lateral petal of a flower in family Fabaceae.
  • woolly: very densely covered with long, more or less matted or intertwined hairs, resembling sheep's wool.

X

  • xeromorph: a plant with structural features (e.g. hard or succulent leaves) or functional adaptations that prevent water loss by evaporation; usually associated with arid habitats, but not necessarily drought-tolerant; cf. xerophyte.
  • xerophyte: a plant generally living in a dry habitat, typically showing xeromorphic or succulent adaptation; a plant able to tolerate long periods of drought; cf. xeromorph.

Z

  • zygomorphic: bilaterally symmetrical; symmetrical about one vertical plane only; applies to flowers in which the perianth segments within each whorl vary in size and shape; cf. actinomorphic, irregular.
  • zygote: a fertilized cell.

See also

Bibliography

Stearn, W.T. 1983. Botanical Latin. David & Charles, North Pomfret, Vermont.

References

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