Banksia menziesii

Banksia menziesii, commonly known as Firewood Banksia, Menzies Banksia or Firewheel Banksia, is a species of small tree or large shrub in the genus Banksia. It is found in Western Australia, from the Perth (32° S) region north to the Murchison River (27° S). The name Firewood Banksia was a result of its quick burning properties and abundance as a source of firewood. The colour of the inflorescences has given rise to more unusual common names such as Port Wine Banksia, Flame Banksia and Strawberry Banksia.

It is one of many banksias first described by the botanist Robert Brown in the early 19th century. A distinctive banksia, it has had an uneventful taxonomic history.

A relatively hardy plant, Banksia menziesii is commonly seen in gardens and amenities plantings in Australian urban areas with mediterranean climates, however its sensitivity to dieback makes it short-lived in climates of summer humidity such as Sydney. Banksia menziesii is widely used in the cutflower industry both in Australia and overseas.

Description

It can be a gnarled tree to 7 metres (23 ft) or lower spreading 1-3 metre (4-10 ft) shrub. The trunk is greyish and rough, the serrated leaves grey-green in colour and 8-25 cm long and up to 4 cm wide, with new growth paler and finely downy. Flowering occurs in autumn and winter.

The inflorescences, ovoid to cylindrical in shape, can be up to 7-8cm wide and 4-12 cm high. They are particularly striking closeup but can look indistinct from a distance. They are most attractive in late bud, the styles contrasting well to the body of the inflorescence, the whole looking like a red- or pink-and white vertical candy striped bloom. The inflorescences are generally a deeper red after colder weather and further into the winter. Some plants have yellow and white inflorescences, others are bronze coloured.

Old flowers usually fall off quickly, with up to 25 large follicles following. These can be prominent and quite attractively patterned when new.

The plant is dependent on fire to reproduce as the follicles open with fire, each follicle producing one or two viable wedge-shaped (cuneate) seeds, separated by a wooden separator. Banksia menziesii is lignotuberous.

Interestingly the colour and level of pigmentation in the seeds foreshadows the eventual colour of the inflorescences. Kevin Collins recalled that for many years pale seeds were discarded by seed collectors who thought they were infertile. Later he learnt that pale seeds yielded yellow-coloured blooms, dark grey the usual red-coloured and black a distinctive bronze-coloured bloom.

Taxonomy

Taxonomic history

Specimens of B. menziesii were first collected by Charles Fraser during Captain (later Admiral Sir) James Stirling's March 1827 exploration of the Swan River. The following year, Alexander Macleay sent some of Fraser's specimens to Robert Brown. Brown formally published the species in his 1830 Supplementum Primum Prodromi Florae Novae Hollandiae, giving it the specific epithet "menziesii" in honor of Archibald Menzies, surgeon-naturalist on the HMS Discovery under George Vancouver, who discovered King George Sound in 1791. Thus the species full name is Banksia menziesii R.Br.. Interestingly, neither Brown nor Menzies ever saw the plant growing.

Under Brown's taxonomic arrangement, B. menziesii was placed in subgenus Banksia verae, the "True Banksias", because its inflorescence is a typical Banksia flower spike. Banksia verae was renamed Eubanksia by Stephan Endlicher in 1847, and demoted to sectional rank by Carl Meissner in his 1856 classification. Meissner further divided Eubanksia into four series, with B. menziesii placed in series Salicinae. When George Bentham published his 1870 arrangement in Flora Australiensis, he discarded Meissner's series, replacing them with four sections. B. menziesii was placed in Orthostylis, a somewhat heterogeneous section containing 18 species. This arrangement would stand for over a century.

In 1891, Otto Kuntze challenged the generic name Banksia L.f., on the grounds that the name Banksia had previously been published in 1775 as Banksia J.R.Forst & G.Forst, referring to the genus now known as Pimelea. Kuntze proposed Sirmuellera as an alternative, republishing B. menziesii as "Sirmuellera menziesii" [sic]. The challenge failed, Banksia L.f. was formally conserved, and Sirmuellera menziesii (R.Br.) Kuntze" is now a nomenclatural synonym of B. menziesii.

Current placement

Alex George published a new taxonomic arrangement of Banksia in his classic 1981 monograph The genus Banksia L.f. (Proteaceae). Endlicher's Eubanksia became B. subg. Banksia, and was divided into three sections. B. menziesii was placed in B. sect. Banksia, and this was further divided into nine series, with B. menziesii placed in B. ser. Spicigerae. Since Brown's original publication had treated all of Fraser's specimens as syntypes for the species, George also chose a lectotype, selecting a tree that Fraser had received from Macleay in May 1828.

In 1996, Kevin Thiele and Pauline Ladiges published a new arrangement for the genus, after cladistic analyses yielded a cladogram significantly different from George's arrangement. Thiele and Ladiges' arrangement retained B. menziesii in series Banksia, placing it in B. subser. Cratistylis along with nine other species. This arrangement stood until 1999, when George effectively reverted to his 1981 arrangement in his monograph for the Flora of Australia series. Under George's taxonomic arrangement of Banksia, B. menziesii's taxonomic placement may be summarised as follows:

Genus Banksia

Subgenus Banksia

Section Banksia

Series Salicinae

Series Grandes

Series Banksia

B. serrata

B. aemula

B. ornata

B. baxteri

B. speciosa

B. menziesii

B. candolleana

B. sceptrum

Series Crocinae

Series Prostratae

Series Cyrtostylis

Series Tetragonae

Series Bauerinae

Series Quercinae

Section Coccinea

Section Oncostylis

Subgenus Isostylis

B. menziesii's resembles no other Banksia; its closest relative was felt by George to be B. speciosa (Showy Banksia) and B. baxteri (Bird's nest Banksia), which differs from B. menziesii in having yellow flowers and leaves with deep triangular lobes. In 2002, a molecular study by Austin Mast showed its closest relatives to be the members of the series Crocinae.

In 2005, Mast, Eric Jones and Shawn Havery published the results of their cladistic analyses of DNA sequence data for Banksia. They inferred a phylogeny very greatly different from the accepted taxonomic arrangement, including finding Banksia to be paraphyletic with respect to Dryandra. A new taxonomic arrangement was not published at the time, but early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons; in this way they also redefined the autonym B. subg. Banksia. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then B. menziesii is placed in B. subg. Banksia.

Variation within the species

B. menziesii in unusually variable in two aspects. Firstly, it varies in habit, growing as a tree for most of its distribution, but usually as a shrub at its northern extents. There is, however, no clear division between the two: they grade together in both form and distribution. Secondly, B. menziesii has more flower colour variants than any other Banksia species, with flowers occurring in a wide range of pinks, plus chocolate, bronze, yellow and greenish variants. Variation in other characteristics is fairly typical of the genus. According to George, B. menziesii is "a clearly defined species", and "no formal division is warranted".

Hybrids

As B. menziesii is not similar to any other Banksia, hybrids are unlikely to occur. The only reported hybrid is a sterile hybrid with B. hookeriana (Hooker's Banksia), found north of Badgingarra by Greg Keighery. Manual cross-fertilisation with B. attenuata has resulted in germination, indicating that these two species are genetically compatible, but natural hybrids are extremely unlikely because the two species flower at different times.

Distribution and habitat

B. menziesii grows primarily in deep sandy soils of the Swan Coastal Plain and Geraldton Sandplains, extending from Waroona in the south to Kalbarri in the north. It is generally limited to the east by the heavy soils of the Darling Scarp, but does grow on isolated patches of sand in the Jarrah Forest and Avon Wheatbelt regions, such as occur near Beverley, Toodyay and Wongan Hills. The easternmost known occurrence is a specimen collected by Roger Hnatiuk in 1979 from north-east of Brookton, about 125 kilometres from the coast.

Together with B. attenuata (Candlestick Banksia), B. menziesii is a dominant component in a number of widespread vegetation complexes of the Swan Coastal Plain, including Banksia low woodland and Jarrah-Banksia woodland. These complexes only occur on deep, well-draining sand; in shallower, seasonally wet soils, B. menziesii and B. attenuata give way to other Banksia species such as B. littoralis (Swamp Banksia) or B. telmatiaea (Swamp Fox Banksia).

On the Geraldton Sandplains to the north, B. menziesii usually occurs as a shrub or small tree emergent above low heath.

Ecology

One study has found that Banksia menziesii also had larger plants with more cones on road verges, with increased availability of nutrients and water.

Cultivation

The plant is fairly easy to grow in a mediterranean climate with good drainage and a light (sandy) soil; however, it is sensitive to dieback, so will be unreliable in conditions with summer humidity or poor drainage. A dwarf form is commonly sold in nurseries. In general, plants encountered in nurseries or gardens are the red-flowered forms, though the bronze-flowered variants appear in the cut flower industry from time to time.

An interesting feature of seed propagation and selection is that the seeds which grow into yellow-flowered plants are pale and unpigmented, while future bronze- and red-flowered plants are dark greyish and black respectively.

References

External links