Campylopus fragilis (Brid.) B.S.G., Bryol. Eur. 1: 164. 1847. Dicranum fragile Brid., J. Bot. 1800(2): 296. 1801. Type. Germany, Erlangen, Hoffmann s.n.

Plants small, tufted, green to yellow-green; stems usually densely tomentose, 0.6–3.5 cm long. Leaves 3–5 mm long, erect-patent, more or less flexuous above when dry, lanceolate, oblong below, subulate above, serrulate toward the apex; costa ending at the apex, in cross section 2/3 the leaf width, lightly ribbed at back, guide cells well developed, dorsal stereids present, ventral hyalocysts present and larger than the guide cells, at base the dorsal stereid band not as wide as the costa, the margins of the costa therefore of 2–3 layers of enlarged hyaline cells; upper cells rhombodial; basal cells rectangular, hyaline, thin-walled, bulging, in dried material frequently remaining full of air on wetting, marginal basal cells narrower but not forming a distinct border, cells just above the hyaline basal cells firm-walled, quadrate; alar cells not differentiated. Brood bodies minute, slender, at times clustered at the stem tips. Setae 5–8 mm long, reddish yellow; capsules erect to slightly curved when dry, 1.0–1.2 mm long; opercula shortly rostrate, 0.5 mm long. Calyptrae 1.0–1.2 mm long, fringed at base.