Dendroceros

Dendroceros
Dendroceros sp. Nees
growing on the bark of a tree
Scientific classification Edit this classification
Kingdom: Plantae
Division: Anthocerotophyta
Class: Anthocerotopsida
Order: Dendrocerotales
Family: Dendrocerotaceae
Genus: Dendroceros
Nees in Gottsche, Lindenb. & Nees
Type species
Dendroceros crispus
(Swartz 1788) Nees 1846
Species

See text

Dendroceros is a genus of hornworts in the family Dendrocerotaceae. 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. 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. 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.

Classification

Cladogram of living Dendroceros
(Cichoraceus)

D. cichoraceus (Montagne 1845) Stephani 1916

(Dendroceros)

D. paivae Garcia, Sérgio & Villarreal 2012

D. javanicus (Nees 1830) Nees 1846

D. validus Stephani 1917

D. breutelii Nees 1846

D. crispus (Swartz 1788) Nees 1846

D. tubercularis Hattori 1944

(Apoceros)

D. cucullatus Stephani 1923

D. difficilis Stephani 1917

(Nodulosus)

D. africanus Stephani 1917

D. borbonicus Stephani 1892

D. granulatus Mitten 1871

D. crispatus (Hooker 1830) Nees 1917

Current classification by Söderström et al. 2016.

Genus Dendroceros Nees 1846

Habitat

Dendroceros grows on humid ground, rocky outcrops, and on the sides of trees. Its name literally means "tree horn".

References

  1. ↑ Gottsche, C.M.; Lindenberg, J.B.G.; Nees von Esenbeck, C.G. (1846). Synopsis Hepaticarum. p. 579.
  2. ↑ 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). ISBN 0-521-66097-1
  3. 1 2 Pressel, S.; Renzaglia, K. S.; (Dicky) Clymo, R. S.; Duckett, J. G. (2018). "Hornwort stomata do not respond actively to exogenous and environmental cues". Annals of Botany. 122 (1): 45–57. doi:10.1093/aob/mcy045. PMC 6025193. PMID 29897395.
  4. ↑ 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. ISBN 0-914-86821-7.
  5. ↑ Duckett, J.G.; Ligrone, R. (2003). "There are many ways of making water-conducting cells but what about stomata?". Field Bryology. 82: 33.
  6. ↑ 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. PMC 7881058.
  7. ↑ Villarreal A., Juan Carlos; Campos S., Laura Victoria; Uribe-M., Jaime; Goffinet, Bernard (2012). "Parallel Evolution of Endospory within Hornworts: Nothoceros renzagliensis (Dendrocerotaceae), sp. nov". Systematic Botany. 37 (1): 31–37. doi:10.1600/036364412X616594. JSTOR 41416933. S2CID 86328103.
  8. ↑ Peñaloza-Bojacá, Gabriel Felipe; Villarreal-Aguilar, Juan Carlos; Maciel-Silva, Adaíses Simone (2019). "Phylogenetic and morphological infrageneric classification of the genus Dendroceros (Dendrocerotaceae; Anthocerotophyta), with the addition of two new subgenera". Systematics and Biodiversity. 17 (7): 712–727. doi:10.1080/14772000.2019.1682080. S2CID 209591279.
  9. ↑ Brinda, John C.; Atwood, John J. "The Bryophyte Nomenclator". Retrieved 6 December 2022.
  10. ↑ Söderström; et al. (2016). "World checklist of hornworts and liverworts". PhytoKeys (59): 1–826. doi:10.3897/phytokeys.59.6261. PMC 4758082. PMID 26929706.