Polytrichaceae

Polytrichaceae Temporal range: Valanginian–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Polytrichum commune
Scientific classification
Kingdom:	Plantae
Division:	Bryophyta
Class:	Polytrichopsida Doweld
Order:	Polytrichales M. Fleisch.
Family:	Polytrichaceae Schwägr.
Genera
See text.

Polytrichaceae is a common family of mosses. Members of this family tend to be larger than other mosses, with the larger species occurring in particularly moist habitats. The leaves have specialized sheaths at the base and a midrib that bears photosynthetic lamellae on the upper surface. These mosses are capable of sustaining high rates of photosynthesis in the presence of ample light and moisture. Unlike all other mosses, the hydroid-based vascular system of these mosses is continuous from stem to leaf and can extract water from the soil through transpiration.^[1] Species in this group are dioicous, though some are monoicous.^[2] In most species, the sporophytes are relatively large, the setae are rigid, and the calyptrae are hairy.^[1] Most species have nematodontous peristomes with 32–64 teeth in their sporangium;^[2] some early-diverging genera instead have a stopper mechanism, which consists of the apical section of the columella, that seals the mouth of the capsule shut prior to dehiscence.^[1]

Classification

class Polytrichopsids order Polytrichales family Polytrichaceae multiple genera	Takakiopsida Sphagnopsida Andreaeopsida Andreaeobryopsida Oedipodiopsida Tetraphidopsida Polytrichaceae Bryopsida
The phylogenetic position of the Polytrichaceae among the eight classes of mosses, based on inferences from DNA sequence data.[3][4]

Genera

Atrichum undulatum

• Alophosia
• Atrichopsis
• Atrichum
• Bartramiopsis
• Dawsonia
• Dendroligotrichum
• Hebantia
• Itatiella
• Lyellia
• Meiotrichum
• Notoligotrichum
• Oligotrichum
• Plagioracelopus
• Pogonatum
• Polytrichadelphus
• Polytrichastrum
• Polytrichum
• Pseudatrichum
• Psilopilum
• Steereobryon

Extinct genera

• †Eopolytrichum Konopka et al., 1997 Cretaceous (Campanian); Gaillard Formation, Georgia, USA
• †Meantoinea Bippus et al., 2017 Cretaceous (Valanginian); Apple Bay locality, Vancouver Island, British Columbia, Canada
• †Polytrichites Britton, 1926 Miocene; Latah Formation, Washington, USA^[5]

References

1. Bell, Neil; Kariwayasam, Isuru; Flores, Jorge; Hyvönen, Jaakko (2021). "The diversity of the Polytrichopsida—a review". Bryophyte Diversity and Evolution. 43 (1): 98–111. doi:10.11646/BDE.43.1.8. Retrieved 19 July 2024.
2. Merrill, Gary L. Smith. "Polytrichaceae". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). New York and Oxford: Oxford University Press. Retrieved 19 July 2024 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
3. Goffinet, B.; W. R. Buck & A. J. Shaw (2008). "Morphology and Classification of the Bryophyta". In Bernard Goffinet & A. Jonathan Shaw (eds.). Bryophyte Biology (2nd ed.). Cambridge: Cambridge University Press. pp. 55–138. ISBN 9780521872256.
4. Goffinet, Bernard; William R. Buck (2004). "Systematics of the Bryophyta (Mosses): From molecules to a revised classification". Monographs in Systematic Botany. Molecular Systematics of Bryophytes. 98. Missouri Botanical Garden Press: 205–239. ISBN 1-930723-38-5.
5. Knowlton, F.H. (1926). "Flora of the Latah Formation of Spokane, Washington, and Coeur d'Alene, Idaho". Shorter contributions to general geology, 1925 (PDF) (Report). Professional Paper. Vol. 140. United States Geological Survey. pp. 17–55, plates VIII-XXXI. doi:10.3133/pp140A.