Banksia blechnifolia

Appearance

''Banksia blechnifolia'' is a prostrate shrub that grows to about 50 cm high and spreads to 2–4 m across. It has thick horizontal stems up to 70 cm long and 0.7–1.0 cm thick that lie on top of the ground. They are covered in fine rusty-brown fur, which turns grey with age.

The leathery herringbone leaves rise vertically from the stems on thick 5–18 cm long petioles, which have two narrow ribs on the undersurface. The leaves themselves are 25–45 cm long, with 8–22 deep lobes on each leaf edge. Narrowly triangular to roughly linear in shape and 2–5 cm long, these lobes are either oppositely or alternately arranged along the leaf midline, and arise at 60–80 degrees.

The leaf blade narrows for the top third of its length to a pointed apex. Flowering occurs from mid September to late November, with the flower spikes, known as inflorescences, arising at the ends of the stems. Up to 20 centimetres high and 9 centimetres wide, they are overall red-brown to salmon-coloured. The individual flowers are reddish pink with a cream base, fading to light brown and then grey as they age. The perianth is 2.8–3.2 cm long, includes a 3.5–5 mm limb and is covered in fine fur. Old flowers remain on the spike, obscuring the developing seed pods known as follicles. Up to 25 in number, these are covered in fur and oval, measuring 2.0–3.0 cm long, by 0.5–1.0 cm high, and 1.0–1.5 cm wide.

The obovate to cuneate seed is 2.0–2.5 cm long. It is composed of the wedge-shaped seed body , measuring 0.9–1.2 cm long by 1.2–1.7 cm wide, and a papery wing. One side, termed the outer surface, is convex and pale greyish brown with irregular pits and the inner surface is dark brown and smooth. The seeds are separated by a sturdy dark brown seed separator roughly the same shape as the seeds with a depression where the seed body sits adjacent to it in the follicle.

The first pair of leaves produced by seedlings, known as cotyledons, are wedge-shaped with a convex apical side and measure 1.0–1.1 cm long by 1.4–1.5 cm wide. Dark green in colour, they are faintly reticulated. The auricle at the base of the cotyledon leaf is pointed and measures 0.2 cm long. The cotyledons sit on a short thick hypocotyl.

Naming

It was first described by Victorian state botanist Ferdinand von Mueller in 1864, and no subspecies are recognised.

Distribution

Endemic to Western Australia, ''B. blechnifolia'' is found in the state's south between Jerramungup and Gibson, and north towards the vicinity of Lake King. It grows in flat areas, on white sands in kwongan or mallee kwongan communities. It is not found within 10 km of the coast.

Habitat

Like many plants in Australia's southwest, ''Banksia blechnifolia'' is adapted to an environment in which bushfire events are relatively frequent. Most ''Banksia'' species can be placed in one of two broad groups according to their response to fire: ''reseeders'' are killed by fire, but fire also triggers the release of their canopy seed bank, thus promoting recruitment of the next generation; ''resprouters'' survive fire, resprouting from a lignotuber or, more rarely, epicormic buds protected by thick bark. ''B. blechnifolia'' and the related ''B. petiolaris'' are in the former category—rapid growing plants killed by bushfire and regenerating by seed—while the other prostrate species are slow growing resprouters.

Like other banksias, ''B. blechnifolia'' plays host to a variety of pollinators—insects such as bees, wasps, ants and flies were all recorded in the 1988 ''The Banksia Atlas'' survey.