Banksia praemorsa grows as a shrub to 4 m (13 ft 1 in) with a relatively thick sturdy trunk that branches quite close to the ground.

[2] English plantsman and botanical artist Henry Cranke Andrews described this species from a cultivated specimen in the conservatory of the Clapham Collection in July 1802.

[4] A specimen that flowered at Kew Gardens the same year was selected as the neotype by Alex George in his 1981 monograph on the genus.

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

Cyrtostylis was found to be "widely polyphyletic", as six of the fourteen taxa in that series occurred singly in locations throughout Thiele and Ladiges' cladogram.

The remaining eight formed a clade that further resolved into two subclades, with B. praemorsa appeared in one of them, alongside media, epica and pilostylis:[9] Since 1998, Austin Mast has been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae.

[10][11][12] Early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg.

[13] Banksia praemorsa is found in scattered colonies along the south coast of Western Australia between Torbay (near Albany) and Cape Riche, where it occurs on the sea-facing side of sand dunes or sand cliffs or hills over limestone; all populations occur within 2 km (1.2 mi) of the coast.

The all-yellow flowered form is often cultivated, and has reached 9 m (30 ft) high at the Banksia Farm in Mount Barker, WA.