Calothamnus phellosus

Calothamnus phellosus is a shrub growing to a height of about 4 metres (10 ft) and a width of about 6 metres (20 ft). Its leaves are needle-like, mostly 25-80 millimetres (1-3 in) long and 0.7-1.1 millimetres (0.03-0.04 in) wide, circular in cross section and tapering to a sharp, prickly point.

The flowers have 5 sepals and 5 petals. The stamens are bright red and are arranged in 5 claw-like bundles, each about 22-40 millimetres (0.87-1.6 in) long. The petals are 4.0-4.5 millimetres (0.16-0.18 in) long. Flowering occurs from September to November and is followed by fruits which are woody, flattened spherical capsules, 7-11 millimetres (0.3-0.4 in) long, often tightly packed together and which develop a corky bark.

Calothamnus phellosus was first formally described in 2010 by Alex George in Nuytsia from a specimen found in the north of the Murchison River near Eurardy. The specific epithet (phellosus) is said to be Greek, meaning "corky", referring to the outer surface of the fruit of this species. In ancient Greek phellosus is not attested. The suffix -osus is not of Greek but of Latin origin. In ancient Greek, phellos (φελλός) is used for "cork" and phellōdēs (φελλώδης) and phellinos (φέλλινος) mean respectively "of cork" and "made of cork".

Calothamnus phellosus occurs in the Avon Wheatbelt, Geraldton Sandplains and Yalgoo biogeographic regions.

Calothamnus phellosus is classified as "not threatened" by the Western Australian government department of parks and wildlife.