Wait-a-while

C. muelleri is a clustering, climbing palm growing up to 20 m (66 ft) in length, with thin stems up to 16 mm (0.63 in) diameter. The pinnate fronds are alternate and more or less sessile. They are up to 1 m (3 ft 3 in) long with 7-13 leaflets on each side and have long recurved spines on the rachis. The leaflets have spines along the midrib on the upper surface and small sharp spurs on their margins. The leaf sheath is densely covered in spines. This species, like others in the genus, produces a modified sterile inflorescence (known as a flagellum) up to 1.2 m (3 ft 11 in) long, which is armed with dozens of strong, recurved barbs that act like grappling hooks to latch on to nearby vegetation and provide support for the plant. Fertile inflorescences are up to 1 m (3 ft 3 in) long and flowering occurs in all months of the year. The fruits are a globose drupe about 12–16 mm (0.47–0.63 in) in diameter, containing a single seed.

Calamus muelleri grows in rainforests and wet sclerophyll forests in subtropical eastern Australia, from around Gympie in Queensland south to the Bellinger and Hastings Rivers in New South Wales.

Laetesia raveni, a species of spider endemic to eastern Australia, builds its web only in two plant species, Calamus muelleri and Solanum inaequilaterum, both of which are spiny plants.