Brachydontium trichodes (F. Weber) Fürnrohr
Family: Seligeriaceae
Synonyms
none recent
NatureServe Conservation Status
G2G4
Distribution
North America. U.S.A. (New Hampshire, North Carolina, Tennessee, Washington). South America. (Columbia). Europe, Asia, Australia (Vitt & Spence 2007).
Habitat
Moist acidic rock (often periodically dry in areas otherwise prone to seepage) at higher elevations, along trails and cliff faces. In the Southern Appalachians apparently restricted to elevations above 5000 ft.
Brief Description and Tips for Identification
Very small, 1-2 mm tall, to 5 mm tall including the sporophyte; gregarious acrocarp.
Monoicous. Capsule with beaked operculum separating from the urn by means of a well differentiated annulus. Calyptra mitrate. Mature capsules when dry striate (with longitudinal ridges), with 16 short peristome teeth, teeth papillose.
Seligeria is similar to Brachydontium in gametophytic characters (Crum and Anderson 1981) but differs in its strong preference for calcareous substrate, absence of well differentiated annulus, and a calyptra that is cucullate (split on one side) rather than mitrate.
A second species of Brachydontium, B. olympicum, occurs with B. trichodes on Mt. Rainier, Washington. It differs from B. trichodes in that it has no peristome. Sporophytic characters are required to identify species within the family Seligeriaceae (Vitt & Spence 2007).
Salient Features
- Leafy shoot 1-2 mm tall found on acidic rock
- Capsule with well developed annulus and 16 peristome teeth
- Calyptra mitrate
References
Crum, H. A., and L.E. Anderson (1981). Mosses of Eastern North America (Vol. 1). Columbia University Press
Vitt, D. H. and J. R. Spence. 2007. Brachydontium. Pages 327–328. In: Flora of North America Editorial Committee (eds.), Flora of North America North of Mexico, Volume 27. Oxford University Press, New York
Habitat
Brachydontium trichodes
On rocks in the trail, rather dry rocks when the photo was taken.
Brachydontium trichodes
Occuring in small fissures within the rock's surface, often along the sides of the rock as indicated by the arrows
Habitat
Brachydontium trichodes
Present on the indicated rock
Brachydontium trichodes
On the indicated rock
Habit
Brachydontium trichodes
Capsules not yet fully formed in late July 1999, from same location as other photos on this page where in September of 2018, capsules are nearly mature suggesting sporophytes regularly mature in late summer/early autumn.
Brachydontium trichodes
Based on the color of the urn's contents, spores have formed but await final maturation as calyptrae are still firmly attached to opercula and capsules are yet to dehisce.
Brachydontium trichodes
The species is monoicous, presumably the smaller, sterile shoots would yield sporophytes in the years to come.
Morphology
Brachydontium trichodes
The arrows indicate the mitrate calyptra whose base is divided into several short lobes.
Brachydontium trichodes
As of September 14, 2018, no fully mature capsules were seen. To demonstrate the annulus, the capsule was artificially ruptured bringing about the premature separation of the operculum from the urn.
Brachydontium trichodes
The striae (ridges) of the capsule's urn are just visible in this prematurely dried capsule. The left image shows an operculum from above (beak removed).
Morphology
Brachydontium trichodes
As in many Seligeriaceae, leaves are subulate with a strong costa