Classification
Class
Bryatae
Family
Dicranaceae Schimp.
 Subordinate Taxa
 Nomenclature
Scientific Name:
Mesotus Mitt. in Hooker, Handb. New Zealand Fl. 461 (1867)
Type Taxon:
Mesotus celatus Mitt.
Etymology:
The generic name probably refers to a perceived (by Mitten) intermediate systematic position of the genus. The obscure meaning of this generic name—derived from mesotes (middle or central position) has been discussed by both Allen (1987) and Meagher (2011).
 Description

Mesotus is monotypic, with the features of the type species, described below.

 Taxonomy

Allen (1987) proposed that Mesotus should be removed from the Dicnemonaceae, where it was placed by Brotherus (1924), and placed it in a monogeneric subfamily, Mesotoideae, within the Dicranaceae. He emphasised the following defining features for the subfamily: "immersed capsules, mitriform calyptrae, conic opercula, rhizoids associated with leaf cells, massive endosporic protonemata, and reduced peristome teeth in which the dorsal trabeculae are more heavily thickened than the ventral trabeculae". However, in a re-examination of the concept of the Dicranaceae based on chloroplast DNA sequence data, La Farge et al. (2002) concluded that the Dicnemonaceae (including Mesotus) are nested within traditional members of the Dicranaceae, and that the Dicranoideae (including Mesotus) forms a robust monophyletic clade. Mesotus is retained in the Dicranaceae here.

 Biostatus
Indigenous (Endemic)
Number of species in New Zealand within Mesotus Mitt.
CategoryNumber
Indigenous (Endemic)1
Total1
 Bibliography
Allen, B.H. 1987: A revision of the genus Mesotus (Musci: Dicranaceae). Journal of Bryology 14: 441–452.
Brotherus, V.F. 1924: Musci (Laubmoose). II. Spezieller Teil. In: Engler, A. (ed.) Die natürlichen Pflanzenfamilien. Edition 2. Bd 10. Engelmann, Leipzig. 143–478.
Fife, A.J. 2019a: Dicranaceae. In: Smissen, R.; Wilton, A.D. (ed.) Flora of New Zealand – Mosses. Fascicle 42. Manaaki Whenua Press, Lincoln.
Fife, A.J. 2019b: Dicranaceae. In: Smissen, R.; Wilton, A.D. (ed.) Flora of New Zealand – Mosses. Fascicle 42. Edition 2. Manaaki Whenua Press, Lincoln.
Goffinet, B.; Buck, W.R.; Shaw, A.J. 2009: Morphology, anatomy, and classification of the Bryophyta. In: Goffinet, B.; Shaw, A.J. (ed.) Bryophyte Biology. Edition 2. Cambridge University Press, Cambridge. 55–138.
Hooker, J.D. 1867: Handbook of the New Zealand Flora: a systematic description of the native plants of New Zealand and the Chatham, Kermadec's, Lord Auckland's, Campbell's, and Macquarrie's Islands. Part II. Reeve, London.
La Farge, C.; Shaw, A.J.; Vitt, D.H. 2002: The circumscription of the Dicranaceae (Bryopsida) based on the chloroplast regions trnL-trnF and rps4. Systematic Botany 27: 435–452.
Meagher, D. 2011: An etymology of Australian bryophyte genera. 2 – Mosses. Muelleria 29: 33–61.