Orthotrichum rivulare

Turner
Muscol. Hibern. Spic., 96, plate 8. 1804.
Illustrated
Treatment appears in FNA Volume 28. Treatment on page 65. Mentioned on page 47, 55.

Plants 1–5 cm, dark green to blackish. Stem leaves erect and loosely appressed when dry, oblong-lingulate, oblong-lanceolate, or ovate-lanceolate, 2.8–5 mm; margins strongly revolute to just below apex, usually irregularly dentate at apex; apex obtuse, flat; basal laminal cells rectangular to short-rectangular, walls thin, not nodose; distal cells 10–13 µm, 1-stratose, papillae 1–3 per cell, conic, small. Specialized asexual reproduction absent. Sexual condition gonioautoicous. Seta 1–1.5 mm. Capsule barely to 3/4 emergent when dry, immersed when moist, oblong to oblong-ovate, 1.5–2.5 mm, strongly 8-ribbed entire length; stomata immersed; peristome double; prostome sometimes present; exostome teeth 8, sometimes splitting to 16, erect, loosely reflexed when old, irregularly papillose, papillae usually confluent forming longitudinal striae; endostome segments 16, occasionally rudimentary, usually of 1 row of cells, finely papillose. Calyptra long-rostrate, papillose, naked. Spores 10–17 µm.


Habitat: Exposed tree roots, base of trees along streams, siliceous boulders at edges of streams and rivers, frequently inundated rock, aquatic habitats
Elevation: low to moderate elevations (0-1000 m)

Distribution

V28 94-distribution-map.gif

Alta., B.C., Calif., Idaho, Nev., Oreg., Wash., Wyo., Europe.

Discussion

Orthotrichum rivulare is distinguished from all other species in the genus by: leaves often obtuse with margins dentate near the apex; calyptra plicate with projecting edges papillose, otherwise smooth and naked; 16 endostome teeth; and stomata completely covered by overarching subsidiary cells. A key differentiating feature from O. euryphyllum is the flat, dentate apex.

Selected References

None.

Lower Taxa

None.

... more about "Orthotrichum rivulare"
Dale H. Vitt +
Turner +
Alta. +, B.C. +, Calif. +, Idaho +, Nev. +, Oreg. +, Wash. +, Wyo. +  and Europe. +
low to moderate elevations (0-1000 m) +
Exposed tree roots, base of trees along streams, siliceous boulders at edges of streams and rivers, frequently inundated rock, aquatic habitats +
Muscol. Hibern. Spic., +
Illustrated +
Orthotrichum rivulare +
Orthotrichum +
species +