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hawkweed

hawkweed

[hawk-weed]
hawkweed, any species of the genus Hieracium of the family Asteraceae (aster family), widely distributed perennials, chiefly of open fields. The small, dandelionlike flower heads are borne in clusters at the top of a long, hairy stem; the basal leaves are also hairy. Some species of the W United States are used for forage; in the East, hawkweeds are generally considered pests. In the fall the orange hawkweed, or devil's-paintbrush, the rattlesnake weed, and the king devil often turn whole fields a ruddy orange or yellow. Other species are red or white; a few are cultivated in rocky soil where other plants cannot grow. In folklore, hawks sharpened their eyesight by eating hawkweed sap. Hawkweed is classified in the division Magnoliophyta, class Magnoliopsida, order Asterales, family Asteraceae.

Any of the approximately 200 species of weedy plants that make up the genus Hieracium, in the composite family, native to temperate regions. Mouse-ear hawkweed (H. pilosella), orange hawkweed (H. aurantiacum), and common hawkweed (H. vulgatum) are widely distributed weeds. Some species are cultivated as garden ornamentals for their attractive flower clusters.

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Hawkweed refers to any species in the very large genus Hieracium and its segregate genus Pilosella, in the sunflower family (Asteraceae).

They are common perennials, occurring worldwide . They are usually small and weedy. Only a few are ornamental plants. Most are considered to be troublesome weeds.

They grow to 5-100 cm tall, and feature clusters of yellow, orange or red flower heads, similar to dandelions, atop a long, fuzzy stalk.

Hawkweed is a slang name taken from folklore which says that hawks would chew on the plant to improve their eyesight.

Hawkweeds are used as food plants by the larvae of some Lepidoptera species including Autumnal Rustic, Broad-barred White, Dot Moth, Hebrew Character, Large Yellow Underwing, Lime-speck Pug and The Shark and also by small beetles.

Taxonomy

Few genera are more complex and have given botanists such a headache due to the great number of apomictic species. Through speciation by rapid evolution, polyploidy, and possibly also hybridisation, this variable genus has given rise to thousands of small variations and more than 10,000 microspecies, each with their own taxonomic name, have been described. The database IPNI provides more than 12,000 named taxa for this genus, including subspecies and synonyms, but it is far from complete.

Attempts have been made to break up this genus in Hieracium (sensu stricto; retaining most species) and Pilosella (about 16 species), based on achene characters and the occurrence of stolons.

Species

The list below is a selection of species for which common names are recorded. A more complete list is given in List of Hieracium species.Hieracium

  • Hieracium albiflorum - White-flowered Hawkweed
  • Hieracium alpinum - Alpine Hawkweed
  • Hieracium amitsokense - Royal Hawkweed
  • Hieracium angmagssalikense - Blackstyle Hawkweed
  • Hieracium argutum - Southern Hawkweed
  • Hieracium atratum - Polar Hawkweed
  • Hieracium aurantiacum - Orange Hawkweed, Devil's Paintbrush
  • Hieracium bolanderi - Bolander's Hawkweed
  • Hieracium bombycinum - Spanish King-devil
  • Hieracium caespitosum - Meadow Hawkweed, Yellow Hawkweed
  • Hieracium canadense - Canadian Hawkweed
  • Hieracium carneum - Huachuca Hawkweed
  • Hieracium cynoglossoides - Houndstongue Hawkweed
  • Hieracium devoldii - Devold's Hawkweed
  • Hieracium fendleri - Yellow Hawkweed
  • Hieracium florentinum - Smooth Hawkweed, King Devil, Pale Hawkweed
  • Hieracium floribundum - Yellow Devil Hawkweed
  • Hieracium glomeratum - Queen Devil Hawkweed
  • Hieracium gracile - Slender Hawkweed
  • Hieracium greenii - Maryland Hawkweed
  • Hieracium groenlandicum - Greenland Hawkweed
  • Hieracium gronovii - Queendevil Hawkweed
  • Hieracium horridum - Prickly Hawkweed
  • Hieracium hyparcticum - Arctic Hawkweed
  • Hieracium inuloides - Butterfly Hawkweed
  • Hieracium ivigtutense - Holsteinsborg Hawkweed
  • Hieracium kalmii - Kalm's Hawkweed
  • Hieracium lachenalii - Common Hawkweed
  • Hieracium laevigatum - Smooth Hawkweed
  • Hieracium lemmonii - Lemmon's Hawkweed
  • Hieracium lividorubens - Cow Hawkweed
  • Hieracium longiberbe - Longbeard Hawkweed
  • Hieracium longipilum - Hairy Hawkweed
  • Hieracium maculatum - Spotted Devil's Paintbrush
  • Hieracium megacephalon - Coastalplain Hawkweed
  • Hieracium musartutense - Musartut Hawkweed
  • Hieracium nepiocratum - Lindenows Fjord Hawkweed
  • Hieracium murorum - Wall Hawkweed
  • Hieracium paniculatum - Allegheny Hawkweed
  • Hieracium pilloselloides - Tall Hawkweed, Glaucous King Devil
  • Hieracium plicatum - Boreal Hawkweed
  • Hieracium praealtum - Kingdevil Hawkweed
  • Hieracium pratense - Yellow Hawkweed
  • Hieracium pringlei - Pringle's Hawkweed
  • Hieracium rigorosum - Rockyscree Hawkweed
  • Hieracium robinsonii - Robinson's Hawkweed
  • Hieracium rusby - Rusby's Hawkweed
  • Hieracium sabaudum - New England Hawkweed
  • Hieracium scabrum - Rough Hawkweed
  • Hieracium scholanderi - Kap Farvel Hawkweed
  • Hieracium scouleri - Woollyweed
  • Hieracium snowdoniense - Snowdonia hawkweed
  • Hieracium stelechodes - Dronning Maries Dal Hawkweed
  • Hieracium stiptocaule - Igaliko Fjord Hawkweed
  • Hieracium sylowii - Brownstyle Hawkweed
  • Hieracium tridentatum - Treetooth Hawkweed
  • Hieracium trigonophorum - Singlehead Hawkweed
  • Hieracium triste - Woolly Hawkweed
  • Hieracium umbellatum - Narrowleaf Hawkweed
  • Hieracium venosum - Rattlesnake Weed
  • Hieracium villosum - Shaggy Hawkweed
  • Hieracium wellwitchii - Silver Mouse-ear
  • Hieracium wrightii - Roughstem HawkweedPilosella
  • Pilosella aurantiaca (Hieracium aurantiacum) - Orange Hawkweed
  • Pilosella officinarum (Hieracium pilosella) - Mouse-ear Hawkweed

References

  • Stace, C. A. 1998. Sectional names in the genus Hieracium (Asteraceae) sensu stricto. Edinb. J. Bot. 55: 417-444.
  • Shetler, Stanmyn; Fet, Galina & Unumb, Ellen A. eds. Flora of the U.S.S.R. Volume XXX: Compositae, Genus Hieracium (translated from Russian), 706 pp., illustr., Washington D.C., Smithsonian Institution Libraries, 2002.


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