Woolly Bush

Appearance

"Adenanthos sericeus" mostly grows as an upright, spreading shrub but occasionally takes the habit of a small tree up to 5 m tall. It has erect branches that are covered in short hairs when young, but these are lost with age. Leaves may be up to 40 mm long, and repeatedly divide by threes into from 5 to 50 narrow laciniae, circular in cross-section, with a diameter of less than 0.5 mm.

Flowers are red, and occur alone or in small groups, hidden within the foliage at the end of branches. As with most other Proteaceae, each flower is composed of a tubular perianth of four united tepals, ending in a structure called a "limb"; and a single pistil, the stigma of which is initially trapped inside the limb, but is released at anthesis. In "A. sericeus", the perianth is bright red, about 28 mm long, hairy on the outside but smooth and hairless inside. The style is about 40 mm long; being much longer than the perianth, it is very sharply bent for as long as the stigma remains trapped within the limb, and then springs erect. The fruit is an oval-shaped achene about 5 mm long.

Naming

This species was first described by Jacques Labillardière in his 1805 "Novae Hollandiae Plantarum Specimen", under the name "Adenanthos sericea". No explicit etymology for the specific name was given, but it is accepted that it is from the Latin "sericeus", in reference to the very soft foliage.

Distribution

"Adenanthos sericeus" has a disjunct distribution spanning about 500 km of the south coast of Western Australia. "A. sericeus" subsp. "sericeus" occurs mostly around King George Sound, extending west as far as Torbay Inlet and east almost to Cape Riche; it sometimes occurs very close to the sea. There is then a gap of over 300 km to the populations of "A. sericeus" subsp. "sphalma" at Cape Le Grand. Another group of "A. sericeus" subsp. "sphalma" occurs 100 km further east at Cape Arid.

Habitat

Both subspecies are calcifuge, occurring only in siliceous sands derived from weathered granite. Thus most populations are associated with granite monadnocks. Though its range is restricted, it is locally common and often dominant. "A. sericeus" subsp. "sphalma" is often found in association with "Nuytsia floribunda", "Kunzea baxteri", and "Xanthorrhoea" species.Both subspecies flower throughout the year, though "A. sericeus" subsp. "sphalma" flowers most between August and December.

It is susceptible to "Phytophthora cinnamomi" dieback.