Shrub or tree 1–12 m, with or without a lignotuber, sometimes suckering. Bark smooth, grey, becoming scaly. Branchlets hirsute, tomentose. Leaves alternate, linear, oblong or narrowly cuneate, 1.5–6 × 0.3–1.3 cm, upper surface hirsute and tomentose, lower surface white tomentose, margins entire or occasionally serrate, slightly recurved to revolute, apex truncate or emarginate, rarely acute; petiole 0.2–0.5 cm long. Inflorescences 5–10 cm long, subtended by persistent, tomentose bracts ~1 cm long. Flowers pale yellow, often grey-tinged in bud; tepals 1.6–2.4 cm long, pubescent outside; style 2–3.1 cm long, straight or curved downwards; old flowers persistent, sometimes falling. Follicles up to 150, narrowly elliptic, 0.7–1.7 × 0.2–0.4 cm, smooth, hirsute; follicles typically opening when mature, but some local variants require burning. Flowering February to May (Australia). George 1999. Distribution AUSTRALIA: New South Wales, South Australia, Tasmania, Victoria. Habitat Woodland, forest and shrubland; sometimes swamps, coastal dunes. USDA Hardiness Zone 8. Conservation status Not evaluated. Illustration Rosser 1993, George 1996; NT160. Cross-reference K189. Taxonomic note Closely related to B. integrifolia, which has larger, whorled leaves and larger flowers.
Banksia marginata is considered to be among the hardiest of the genus, tolerating –10 ºC, as well as coastal conditions and dry soil when mature (Moore 2004). It has narrower leaves than B. integrifolia, but they are slightly glossier above. The inflor escence is also pale yellow, and produced in winter or early spring in the northern hemisphere. It is 9 m tall, 35 cm dbh, in the mild climate at Guincho in Ireland, and has reached significant size in the garden of Tim Pyner in Southend, Essex (Johnson 2007). Plants are also well established at Wakehurst Place, where they have flowered. This is certainly a species worth experimenting with away from the mildest places.