Calothamnus formosus

Calothamnus formosus is a large, spreading, densely branched shrub growing to a height of about 2.5 metres (8 ft), sometimes higher, with thick bark on the older stems. Its leaves are crowded on the ends of the younger branches, 40-90 millimetres (2-4 in) long, 0.8-1.2 millimetres (0.03-0.05 in) wide, linear, almost circular in cross section and tapering to a sharp but not prickly point.

The flowers are crimson and arranged in short clusters of 3 to 5, usually on the older, leafless stems. The petals are thin and papery, 3.5-6 millimetres (0.1-0.2 in) long. The stamens are arranged in claw-like bundles with 26 to 32 stamens per bundle. The claws are yellow-green near the base but otherwise crimson. Flowering occurs from August to December and is followed by fruits which are woody, roughly cylindrical capsules, 6.6-8 millimetres (0.26-0.31 in) long, 5-6 millimetres (0.20-0.24 in) in diameter and have a warty surface.

Calothamnus formosus was first formally described in 1984 in Nuytsia by Trevor Hawkeswood from a specimen found on a roadside about 65 kilometres (40 mi) south east of Denham. The specific epithet (formosus) is a Latin word meaning “beautifully formed” or "handsome".

There are two subspecies:

• Calothamnus formosus subsp. formosus, which has leaves that are mostly less than 70 millimetres (3 in) long and occurs in the Shark Bay area
• Calothamnus formosus subsp. rigidus, which has leaves that are mostly more than 70 millimetres (3 in) long and occurs between the Overlander Roadhouse and Yuna district

Calothamnus formosus is found in and between the Shark Bay and Yuna districts in the Carnarvon, Geraldton Sandplains and Yalgoo biogeographic regions. It grows in sand on sandplains.

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