Dendroceros is a genus of hornworts in the familyDendrocerotaceae.[2] The genus contains about 51 species native to tropical and sub-tropical regions of the world.
Description
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]
Dendroceros grows on humid ground, rocky outcrops, and on the sides of trees. Its name literally means "tree horn".
References
^Gottsche, C.M.; Lindenberg, J.B.G.; Nees von Esenbeck, C.G. (1846). Synopsis Hepaticarum. p. 579.
^Renzaglia, Karen S. & Kevin C. Vaughn. (2000) "Anatomy, development and classification of hornworts", pages 1-20 in A. Jonathan Shaw & Bernard Goffinet (Eds.), Bryophyte Biology. (Cambridge: Cambridge University Press). ISBN0-521-66097-1
^Schuster, R.M. (1992). The Hepaticae and Anthocerotae of North America East of the Hundredth Meridian. Vol. 6. Chicago: Field Museum of Natural History. pp. 825–858. ISBN0-914-86821-7.
^Duckett, J.G.; Ligrone, R. (2003). "There are many ways of making water-conducting cells but what about stomata?". Field Bryology. 82: 33.
^Frangedakis, E.; Shimamura, M.; Villareal, J.C.; Li, F.-W.; Tomaselli, M.; Waller, M.; Sakakibara, K.; Renzaglia, K.S.; Szövényi, P. (2021). "The hornworts: morphology, evolution and development". New Phytologist. 229: 740. doi:10.1111/nph.16874.
