Desmoncus


Desmoncus is a genus of mostly climbing, spiny palms native to the Neotropics. The genus extends from Mexico in the north to Brazil and Bolivia in the south, with two species present in the southeastern Caribbean.

Description

Desmoncus is best known as a genus of climbing palms. Twenty-three of the 24 species recognised by Andrew Henderson in his revision of the genus are climbers; only one, D. stans is free-standing. Almost all Neotropical climbing palms belong to Desmoncus—the one exception being Chamaedorea elatior.
's drawing of Desmoncus polyacanthos shows the features of the leaf and the inflorescence with its associated bract.
-like structures called acanthophylls.
Desmoncus leaves are pinnately compound and are made up of a leaf sheath, petioles, rachis, and individual leaflets. The ends of the leaves are modified into a climbing structure called a cirrus. Instead of leaflets, the cirrus usually has grappling hook-like structures called acanthophylls; in some species the cirrus is less well developed and is almost absent in D. stans, the non-climbing species.
All parts of the leaves, including the leaflets themselves, are covered with spines. Most species have straight spines that are over long, but a few species have curved spines that are less than 1 cm long.

Taxonomy

John Dransfield and colleagues put Desmoncus in the subfamily Arecoideae, the tribe Cocoseae and the subtribe Bactridinae, together with Aiphanes, Acrocomia, Astrocaryum and Bactris.
The genus was described by Carl Friedrich Philipp von Martius in 1824. The first species described was D. polyacanthos. Martius later described six additional species that he placed in the genus. In this 1881 Flora Brasiliensis, Carl Georg Oscar Drude recognised 17 species. João Barbosa Rodrigues recognised 28 species in his 1903 work Setum Palmarum Brasiliensis.
Max Burret published a revision of the entire genus in 1934. Burret described nine new species and ended up recognising a total of 41 species. In the 1940s, Liberty Hyde Bailey added 14 additional species to the genus Desmoncus. Jan Wessels Boer rejected the species concept used by Bailey, Barbosa Rodrigues, and Burret as being too narrow and ended up recognising only seven species In his 2011 revision of the genus, Andrew Henderson recognised 24 species.

Distribution

Desmoncus ranges from Mexico in the north to Bolivia and Brazil in the south. Most species occur at lower elevations, but some species range as high as above sea level. The species are mostly found in lowland tropical rainforest. Twelve species occur in Colombia, the most species-rich country, while 10 are found in Brazil.

Species