Notothylas is a genus of hornworts in the family Notothyladaceae. The genus is found globally, but is usually overlooked. It is the smallest of all the hornworts, with a yellow-green gametophyte thallus that is seldom more than a centimeter in diameter, and usually much smaller. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... This is an article about the non-vascular plants known as hornworts. ... Genera Anthoceros Dendroceros Folioceros Megaceros Notothylas Phaeoceros Hornworts (or horned liverworts) are a group of non-vascular plants comprising the class Anthocerotae. ... In biology, a species is the basic unit of biodiversity. ... In biology, a genus (plural genera) is a grouping in the classification of living organisms having one or more related and morphologically similar species. ... Families & Genera Anthocerotaceae Anthoceros Folioceros Leiosporoceros Phaeoceros Sphaerosporoceros Dendrocerotaceae Dendroceros Megaceros Notoceros Notothyladaceae Notothylas Hornworts are a group of bryophytes, or non-vascular plants, comprising the division Anthocerotophyta. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... A gametophyte is the haploid structure or phase of life of a sexually reproducing plant. ... Thallus is an undifferentiated vegetative tissue (without specialization of function) of some non-mobile organisms, which were previously known as the thallophytes. ... cm redirects here, alternate uses: cm (disambiguation) A centimetre (symbol cm; American spelling: centimeter) is an SI unit of length. ...

The genus Notothylas is also unusual among hornworts in that the sporophyte is bullet-shaped and does not grow very large (less than two millimeters). The sporophytes grow outwards rather than upwards, and like Megaceros, there are no stomata on the surface of the sporophyte. The elater cells do not grow helical thickenings. A sporophyte is the diploid structure or phase of life of a sexually reproducing plant. ... | ... An elater is a cell (or structure attached to a cell) that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. ... This article is about the shape. ...

A number of classification systems place Notothylas in its own order Notothyladales (frequently misspelled Notothylales in the literature). This classification is based on the assumption that the unique physical characteristics of the genus reflect an early divergence from other hornworts. However, this assumption has not yet been rigorously tested or supported by either phylogenetic analysis or fossil evidence. For the present, Notothylas is usually placed in the Anthocerotales with all other species of hornworts.

References

• Asthana, A. K. & Srivastava, S. C. (1991). Indian Hornworts (A Taxonomic Study). J. Cramer: Bryophytorum Bibliotheca, Band 42. ISBN 3-443-62014-0.
• Hässel de Menendez, G. G. (1988). A proposal for a new classification of the genera within the Anthocerotophyta. J. Hattori Bot. Lab. 64: 71-86.
• Hicks, Marie L. (1992). Guide to the Liverworts of North Carolina. Durham, NC: Duke University Press. ISBN 0-8223-1175-5.
• Prihar, N. S. (1961). An Introduction to Embryophyta, Volume I. Allahbad: Central Book Depot.