Peter Olde and Neil Marriott acknowledge Ann Pilkington of Kirkalocka, "who discovered Banksia rosserae and who drew it to our attention through various third parties.

According to Collins, Cullen had visited Kirkalocka in search of an undescribed Grevillea species mentioned in the writings of Charles Gardner (now published as G. kirkalocka); in addition to finding the Grevillea, he also found two B. rosserae plants growing on the top of an orange sand dune.

In 2001, Olde, Marriott and Keith Alcock visited the area in search of the undescribed Grevillea species.

Two months later, a party of botanists and Banksia enthusiasts visited the area, and observed the flowers for the first time.

Its leaves are virtually indistinguishable from narrow-leaved forms of B. laevigata (Tennis Ball Banksia), and like that species it has condensed, roughly spherical inflorescences, and slender styles.

"[1] Although most of the land around Mount Magnet has the heavy clay soil and Acacia aneura (Mulga) scrub common throughout semi-arid Western Australia, the area on which B. rosserae occurs is unusual in having deep yellow sand and laterite.

[3] The combination of a bushfire followed by several seasons of cyclonic storms probably only occurs every few hundred years, suggesting that opportunities for seedling recruitment are extremely rare.

All known plants appear to be in very good health and free of pests; it seems they are not eaten or damaged by the area's kangaroos, goats and sheep.

[2] Bushfire clearly poses no threat; and the area is free from Phytophthora cinnamomi dieback, a scourge of most other western Banksia species.

[2] In fact, the only perceived threat is the rarity of conditions conducive to seedling recruitment: "it may well be that this banksia has become so adapted to its harsh environment that its long-term future in the wild is in doubt.

In 2003, Kevin Collins reported that "early trials have proven good seed viability and rapid young seedling development".

[2] The following year Neil Marriott reported that "seedlings germinate well with smoked water during spring, and young plants establishing here in deep granite sands and sandy loams at Stawell are growing slowly but steadily."