Orthotrichum Moss

Orthotrichum gymnostomum Bruch; Brid. Bryol
Univ. 1:782. 1872.
Plants in yellowish-green tufts, reddish-brown within; stems 0.5-1 cm. tall, erect, rigid, usually simple, sometimes with one or more clavate innovations; leaves when dry closely imbricate, when moist spreading, oblong-ovate, concave, carinate, broadly obtuse, 2-2.5 mm. long, the margins strongly involute except at the base, the apex often almost cymbiform; costa narrow, disappearing below the apex; middle basal leaf-cells broadly linear, quadrate at the basal angles, the upper oblong-rhomboidal, the apical oval or roundish, about 15 y. in diameter, each with one or two stout papillae; perichaetial leaves similar but longer, oblong-lanceolate, often plane at the apex; dioicous; male plants smaller, sometimes in separate tufts; seta very short; capsules immersed, oblong-ovate, oblong when dry and empty, rounded at the truncate base, the neck shorter than the spore-sac, the 8 ribs yellowish, each composed of 2-4 rows of thick-walled cells; calyptra plicate, conical, without hairs but rough and black at the apex; only a few superficial stomata near the mouth of the capsule ; operculum narrowly conical from a convex base; spores maturing in spring.
Type locality: Europe.
Distribution: On aspens; Upper Sandy Point, Newfoundland (Waghorne) ; Europe; Japan.