Banksia penicillata

A shrub, usually to about 4 m tall, without a lignotuber.

It is found in restricted areas in the central coast, tablelands and central western slopes, mainly in the Blue Mountains (Wollemi National Park), on sandstone cliffs or steep rocky slopes. It grows in dry sclerophyll woodland and forests.

The leaves are whorled, somewhat stiff and leathery, elliptic to obovate, to 12 cm long and 4 cm wide with lobed to toothed margins. Olive to green to blue-green on upper surface and white on under surface, sometimes with yellow to rusty hairs on mid and secondary veins. This species can produce red-brown hairy new growth.

The inflorescences of banksias are generally referred to as spikes or a spike-like structure which consists of fused racemes of paired flowers (hence it gets referred to as a conflorescence). There can be 100s of flowers in each spike. The flowers of banksias have 4 tepals (petals or sepals) in a tubular formation, 4 anthers hidden inside and an elongated carpel (female part) where the style extends outwards forming the edge of the spike (somewhat similar to individual grevillea and hakea flowers).
In this species, the spikes are generally to 19 cm long and up to 6 cm wide, with each flower thin but up to 3 cm long, yellow-green with green-blue colouring when in bud (a useful identification feature). At times, inflorescences can display other colours. They can also have a sweet smell.

The spike then turns into a cone-like structure of follicles; a fruit which splits open on one side. Each follicle has one or two winged seeds which is actually a fruit in itself called a samara. The follicles can take a long time to mature and open, usually needing a fire or a drying out period. Each “cone” can produce a fair amount of seed with this species having follicles to 15 mm long with over 100 follicles per “cone”.