B. blechnifolia is one of several closely related species that grow as prostrate shrubs, with horizontal stems and leathery, upright leaves.

Found in sandy soils in the south coastal region of Western Australia in the vicinity of Lake King, B. blechnifolia is non-lignotuberous, regenerating by seed after bushfire.

The leathery herringbone leaves rise vertically from the stems on thick 5–18 cm (2–7 in) long petioles, which have two narrow ribs on the undersurface.

Narrowly triangular to roughly linear in shape and 2–5 cm (3⁄4–2 in) long, these lobes are either oppositely or alternately arranged along the leaf midline, and arise at 60–80 degrees.

[2] The individual flowers are reddish pink with a cream base, fading to light brown and then grey as they age.

[3] Victorian state botanist Ferdinand von Mueller first recounted Banksia blechnifolia in 1864,[4] from material collected in 1861 by a G.

[5] Von Mueller held it to be close to B. repens,[4] but in his 1870 arrangement, English botanist George Bentham regarded it as synonymous with that species.

[6] The species was then mostly forgotten until 1931, when it was collected again by Western Australian botanists William Blackall and Charles Gardner near Middle Mount Barren.

[3] In 1996, botanists Kevin Thiele and Pauline Ladiges published an arrangement informed by a cladistic analysis of morphological characteristics.

[7] George later published an updated version of his 1981 arrangement in his 1999 treatment of Banksia for the Flora of Australia series of monographs.

The placement of B. blechnifolia in George's 1999 arrangement may be summarised as follows:[8] Since 1998, American botanist Austin Mast has been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae, which includes Banksia.

[12] In a 2013 cladistics study, evolutionary scientists Marcell Cardillo and Renae Pratt found that B. blechnifolia diverged from a lineage that gave rise to B. goodii, B. gardneri and B.

[13] 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.

[3] Like many plants in Australia's southwest, Banksia blechnifolia is adapted to an environment in which bushfire events are relatively frequent.