Calamus (palm)


Calamus is a genus of flowering plants in the palm family Arecaceae, and is one of several genera known as rattan palms. There are an estimated 400 species in this genus, all native to tropical and subtropical Asia, Africa, and Australia.

Description

Species in this genus are mostly climbers with long, slender, flexible stems, but some are erect shrubs and some have no apparent stem. They may be clustering or single-stemmed. The leaves are with an even number of leaflets, in the climbers they may be variously barbed or clothed in spines. Climbers also produce armed tendrils – either from the leaf sheath, in which case it is known as a 'flagellum', or as an extension of the midrib and known as a 'cirrus'. Climbing species will often reach the forest canopy, and one plant was recorded as being long. In some species, such as Calamus rudentum, the inflorescence also has a flagellum.
All species are dioecious, meaning that male and female inflorescences are produced on separate plants. They both arise from the and are pendant and branched, and may variously have barbs, spines or cirri. The fruit rarely contain more than one seed, the thin sarcotesta is covered by an external layer made up of rows of small overlapping scales similar in appearance to a snakeskin.

Taxonomy

Calamus is the sole genus in the subtribe Calaminae, tribe Calameae, subfamily Calamoideae. It includes over 400 species after the remaining genera of Calaminae were subsumed within it in 2015, in preparation for a wide review of the genus. It is known to be non-monophyletic, and a reliable description of the genus is not possible due to a lack of uneqivocal synapomorphies.

Distribution

The genus is distributed from Africa through southeast Asia and Australia to islands of the western Pacific. The bulk of the species occur in Asia, with one species in Africa and eight in Australia.

Uses

Various species are used to produce the rattan cane for making furniture. Many species were also used in tribal cultures – Indigenous Australians used various parts for shelters, baskets, axe handles, fish traps and fishing lines, as well as eating the fruit and young shoots. Some species may have medicinal properties.

Species

, Plants of the World Online recognises 416 species: