#eriophyidae

Currently the most common of the three accepted subspecies of the plant - one is found in Queensland, and the other in the Blue Mountains west of Sydney.

One of the four species of Banksia collected by Sir Joseph Banks in his role as naturalist on Cook's first expedition to the Pacific in 1770. Also the most widely distributed species, from Victoria and Central Queensland in coastal dunes and up into the mountains. It can grow into a gnarled tree up to 35 metres in height, but in exposed coastal areas might not get bigger than a small shrub. The leaves are dark green above and and white underneath.

The infloresences produce abundant nectar, but only for 4 to 11 days - a very short period, for a Banksia. Also unusual is the fact they don't require fire to release and germinate the seeds. They DO possess the mat-like proteiod roots used by many Proteaceae to access soil nutrients even in soil as awful as Australia's.

Widely planted in Australian gardens, and has been used for bush revegetation and dune stabilisation. The timber is decorative but poorly suited to most construction purposes, and indigenous peoples collected the nectar, used the cones as candles after soaking them in fat, and used the flowerspikes as hairbrushes. Banksia species can be very picky about over-fertilised soil and other issues such as Phytophthora cinnamomi dieback, but the Coast Banksia is so hardy it has weed potential.

As for the galls on the cones - a very common sighting on Banksia integrifolia, but I have yet to find an ID on the genus let alone species responsible.

A genus of over 900 Eriophyid mites that cause galls and blistering on a wide range of plants. Some are agricutral pests, and others are useful biological controls of invasive weeds.

The species in this case is almost certainly Aceria erinea, the Walnut Felt Gall Mite - such excessive hair growth on the underside of the leaf is called a felt gall or erineum. Chemicals injected by the mites as they feed on the leaf cause excessive cell growth, enlarging the blister and producing the hairs that protect the arachnids from predators and dehydration.