Alex George described the plant in his 1981 monograph of the genus Banksia as a variety of B. integrifolia, but later reclassified it as a separate species.

The species is found in wet sclerophyll forest and rainforest margins on sandy soils.

They are a smooth shiny green above and white below with a prominent midrib covered in red-brown hair.

All old flower parts fall away as up to 50 oval follicles develop on the bare woody spike.

Furry at first, they become smooth with age and open when ripe,[4] and their two half-oval valves split to release the one or two seeds they contain.

[6] The southernmost populations of B. aquilonia are separated from the northernmost B. integrifolia occurrence by 200 km (120 mi),[9] hence location is helpful in identification.

[6] Field volunteers for The Banksia Atlas recorded plants with large adult and juvenile leaves up to 38 cm (15 in) long along the Tully to Mission Beach Road, and a population of smaller shrub-sized plants to 3 m (9.8 ft) high with small narrow leaves 13 cm (5.1 in) long and 0.4 cm (0.16 in) wide at Coronation Lookout in Wooroonooran National Park, plants with normal morphology occurring further down the mountain.

On this basis they would have liked to promote it to species rank, but did not because their inferred phylogeny suggested that this taxon arose from within B. integrifolia.

[11] This example has since been held up as an interesting case study on how the concept of species should be defined, as it presents the problem of "a monophyletic group comprising a paraphyletic basal group of incompletely differentiated geographic forms within which is nested at least one divergent, autapomorphic taxon that invites treatment as a species.

"[12] George promoted it to species rank on the basis of its distinctive leaf arrangement and midrib in 1996.

[6] Since 1998, American botanist Austin Mast and co-authors have been publishing results of ongoing cladistic analyses of DNA sequence data for Banksia and Dryandra.

[13][14][15] Early in 2007, Mast and Thiele rearranged the genus Banksia by merging Dryandra into it, and published B. subg.

[5] It grows in wet sclerophyll forest or rainforest margins,[7] on plateaus, ridges, slopes and low-lying swampy areas on sandy or rocky soils,[5] generally of granitic origin,[6] or sometimes clay.

[5] It commonly grows with tree species such as the pink bloodwood (Corymbia intermedia), forest red gum (Eucalyptus tereticornis), swamp turpentine (Lophostemon suaveolens), forest oak (Allocasuarina torulosa), and black sheoak (A. littoralis), and understorey species such as coin spot wattle (Acacia cincinnata) and yellow wattle (A. flavescens).