February 13, 2020

Palms that Branch

Doum Palm, Hyphaene thebaica, Samburu National Park, Kenya
Image by Harvey Bernstein
Palms are not usually considered branching plants, although individuals occasionally develop crowns due to injury or disease. Most species that branch do so at the base of the original stem. A few species exhibit aerial branching, growing multiple crowns from a single trunk. Genera may include species that branch basally, aerially, or both. The genera Hyphaene, Nannorrhops, and Nypa include palms that display this atypical growth form.
Hyphaene is a genus of approximately ten species widely distributed across Africa, coastal Arabia, and the west coast of India. Some species of Hyphaene develop multiple trunks that are considered basal branches; others branch more conventionally. 
Painting by Marianne North, 1880
Hyphaene thebaica, Doum Palm, is the branching palm depicted in classic views of Egyptian life along the Nile. Hyphaene dichotoma is an Indian species that is threatened with habitat loss. Where they naturally occur, Hyphaene are used for thatch, timber, fuel, and to make palm wine.
Nannorrhops ritchiana, Mazari Palm, belongs to a monotypic (single species) genus found in Arabia, Iran, Afghanistan, and Pakistan in semi-desert areas. Typical mature individuals branch both basally and aerially. Nannorrhops exhibits a dichotomous, monocarpic branching pattern. Twin branches fork at the top of an erect trunk. One branch develops a single terminal inflorescence and then dies back. The second eventually develops in own inflorescence. Nannorrhops is used for thatch, fiber, and fuel in its native range.
Mazari Palm, Nannorrhops ritcheana, in Pakistan
Image by Naeem Javid Muhammad Hassani
The peculiar monotypic genus Nypa, the Mangrove Palm, displays non-basal trunk branching, but the very short trunks are recumbent and hidden beneath the mud. Nypa occurs along rivers and in estuaries of tropical Asia and Northern Australia.
Mangrove palm, Nypa fruticans
Image by Cun Cun


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