Dendroceros is a genus of hornworts in the family Dendrocerotaceae.[2] The genus contains about 51 species native to tropical and sub-tropical regions of the world.
Dendroceros | |
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Dendroceros sp. Nees growing on the bark of a tree | |
Scientific classification | |
Kingdom: | Plantae |
Division: | Anthocerotophyta |
Class: | Anthocerotopsida |
Order: | Dendrocerotales |
Family: | Dendrocerotaceae |
Genus: | Dendroceros Nees in Gottsche, Lindenb. & Nees[1] |
Type species | |
Dendroceros crispus (Swartz 1788) Nees 1846
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Species | |
See text |
The epiphytic and epiphyllous Dendroceros is the only desiccation-tolerant hornwort genus.[3] The gametophyte is yellowish-green and usually less than one-half cm wide. The thallus branches in a bifurcating pattern. In the subgenus Apoceros, there are cavities in the central strand of the thallus. The edges of the thallus are only a single layer of cells thick and have an undulating margin. It is common to find symbiotic colonies of blue-green bacteria (usually Nostoc) growing among the cells. Under a microscope, the epidermal cells have trigones.
The sporophyte is erect when mature, growing up to 5 cm tall. Unlike many hornworts, the surface of the Dendroceros sporophyte lacks stomata, as do the sporophytes of the related genera Megaceros and Nothoceros.[4][5][3][6] The interior of the sporophyte differentiates into a central column and a surrounding mass of spores and elater cells, with a distinct spiral. The spores are green and multicellular with an ornamented surface.[7]
Cladogram of living Dendroceros[8][9] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Current classification by Söderström et al. 2016.[10]
Genus Dendroceros Nees 1846
Dendroceros grows on humid ground, rocky outcrops, and on the sides of trees. Its name literally means "tree horn".