Calothamnus tuberosus is a compact, highly branched shrub growing to a height of about 2.5 metres (8 ft) or more.
Its leaves are crowded at the ends of the branches and are 50–80 millimetres (2–3 in) long, 1.0–2.5 millimetres (0.04–0.1 in) in diameter, stiff, cylindrical in shape and taper to a prickly point.


The flowers are rich red and in small dense spikes amongst the leaves or on the older, leafless branches .
The 4 petals are 3–4 millimetres (0.1–0.2 in) long, thin, papery and orange to brown.
The stamens are arranged in 4 claw-like bundles, all 22–28 millimetres (0.9–1 in)usually with 12 to 16 stamens per bundle.
Flowering occurs from November to January, although sometimes in other months, depending on weather conditions.
Flowering is followed by fruits which are woody, almost spherical capsules, 4–5 millimetres (0.16–0.20 in) in diameter.
Calothamnus tuberosus is a compact, highly branched shrub growing to a height of about 2.5 metres (8 ft) or more. Its leaves are crowded at the ends of the branches and are 50–80 millimetres (2–3 in) long, 1.0–2.5 millimetres (0.04–0.1 in) in diameter, stiff, cylindrical in shape and taper to a prickly point.

The flowers are rich red and in small dense spikes amongst the leaves or on the older, leafless branches . The 4 petals are 3–4 millimetres (0.1–0.2 in) long, thin, papery and orange to brown. The stamens are arranged in 4 claw-like bundles, all 22–28 millimetres (0.9–1 in)usually with 12 to 16 stamens per bundle. Flowering occurs from November to January, although sometimes in other months, depending on weather conditions. Flowering is followed by fruits which are woody, almost spherical capsules, 4–5 millimetres (0.16–0.20 in) in diameter.
Calothamnus tuberosus