Trematodon

Trematodon longicollis, from Hong Kong Flora.

Belongs within: Dicranaceae.

Trematodon is a genus of mosses found worldwide but primarily in temperate environments. Together with the closely related but generally smaller Bruchia, it is characterised by a conspicuous, highly stomatose neck on the capsule. Species include Trematodon ambiguus, which has the leaves narrowing close to the base to a long seta, and is widespread in temperate Eurasia and North America.

Characters (from Zander 2007): Leaves usually contorted when dry, lanceolate to broadly subulate from an ovate or oblong sheathing base, 1.5-4 mm, apex acute to narrowly obtuse, margins entire or with a few teeth apically; costa subpercurrect to excurrent as a subula; distal laminal cells subquadrate or short-rectangular. Perichaetial leaves distinctly larger than the cauline, convolute-sheathing. Seta elongate, 0.5-1.5 mm. Capsule long-exserted, cylindric with neck strongly differentiated, conic to long-cylindric; peristome absent or present, of 16 simple, forked or perforate teeth, vertically barred on external surface; operculum differentiated, obliquely long-rostrate. Calyptra cucullate. Spores medium-sized, 20-30 µm, papillose.

<==Trematodon Michx. 1803 SK02
    |--T. adaequans Geh. ex Roth. 1913 [incl. T. abruptus (n. n.)] SK02
    |--T. ambiguus [=Dicranum ambiguum] D24
    |--T. amoenus (Müll.Hal.) Stone & Scott 1976 [=Bruchia amoena] SK02
    |--T. baileyi Broth. 1891 [=T. braileyi (l. c.)] SK02
    |--T. brachyphyllus Müll.Hal. 1898 [=T. trachyphyllus (l. c.)] SK02
    |--T. flexipes Mitt. 1859 [incl. T. alpinus, T. pygmaeus (nom. inv.)] SK02
    |--T. latinervis SK02
    |--T. longescens Müll.Hal. 1898 SK02
    |--T. longicollis Michx. 1803 [incl. T. acutus Müll.Hal. 1848] SK02
    |--T. mackayi (R.Br.bis) Broth. 1901 [incl. T. weymouthii] SK02
    `--T. suberectus Mitt. 1867 SK02

Nomen nudum: Trematodon whiteleggei Broth. ex Watts & Whitel. 1902 SK02

*Type species of generic name indicated

REFERENCES

[D24] Dixon, H. N. 1924. The Student's Handbook of British Mosses 3rd ed. V. V. Sumfield: Eastbourne.

[SK02] Streimann, H., & N. Klazenga. 2002. Catalogue of Australian Mosses. Flora of Australia Supplementary Series 17. Australian Biological Resources Study: Canberra.

Zander, R. H. 2007. Bruchiaceae Schimper. In: Flora of North America Editorial Committee (eds) Flora of North America North of Mexico, vol. 27, pp. 433-439. New York and Oxford.

Last updated: 21 December 2017.