Banksia plants belong to a genus of around 170 species native to Australia. They also belong to the Proteaceae plant family, which is an ancient family of flowering plants that dispersed and diversified throughout Gondwana before the supercontinent disintegrated.

With about 1600 species, Proteaceae is one of the plant groups that dominate the southern hemisphere flora. Banksia plants take many forms, from trees up to 30 meters tall, to woody shrubs, to a few prostrate species.

The leaves vary greatly between species, with sizes varying from 1.0–1.5 centimeters long up to 45cm long. The young leaves are velvety and often brownish or yellow in color, while the mature leaves are green or dark green, hard to touch and most species have serrated edges.

Leaves are usually arranged along the branches in irregular spirals, but in some species, they are crowded together in whorls. The most distinguishing feature of banksias is the flower spike, which is an elongated inflorescence consisting of a woody axis covered in tightly-packed pairs of flowers attached at right angles.

A single flower spike generally contains hundreds or even thousands of flowers; the most recorded is around 6000 inflorescences in Banksia grandis.

Source