Banksia elderiana grows as a tangled and bushy shrub to 3 m (9.8 ft) in height, with new growth covered densely with brown fur.

[8] Alex George placed Banksia elderiana in the series Cyrtostylis, and felt its closest relative to be B. lullfitzii on the basis of its similar leaves and propensity of both to form tangled shrubs.

However, he conceded was heterogeneous, and also noted its affinities with the series Tetragonae, containing other banksias with upside down inflorescences such as B. lemanniana, B. caleyi and B. aculeata.

[9] In 1996, Kevin Thiele and Pauline Ladiges published the results of a cladistic analysis of morphological characters of Banksia.

They united B. elderiana with the Tetragonae on the basis of upside down inflorescences and straight styles that do not bend once freed from the perianth at anthesis, a feature not seen in many other banksia species.

[11] It has been shown to have a low to moderate susceptibility to dieback from the soil-borne water mould Phytophthora cinnamomi, unlike many Western Australian banksias.