Orthotrichum assimile

Asexual reproduction by fusiform gemmae 5–7 cells long on leaves. Loose or dense tufts mostly on trees, rarely on calcareous or non-calcareous rocks, 3.5–12 mm tall, yellow to olive-green. Stems orange with frequent orange- to red-brown rhizoids, tomentose toward base. Leaves erect- to wide-spreading when moist, erect-appressed when dry, ovate-lanceolate to lanceolate, 1.8–4.1 mm long, 0.6–1 mm wide, carinate; apex rounded-acute, acute or acuminate; costa strong, ending below apex; margin entire, rarely dentate apically, recurved, without a border; laminal cells in apical half round to elliptic, isodiametric, 6.5–21 μm long, 6.5–20 μm wide, each with 2–4 mostly unbranched papillae; basal laminal cells rectangular, 15–100 μm long, 7–10 μm wide, smooth, forming a region that transitions into shorter cells at c. 1/4–1/3 the way to leaf apex. Seta to 1 mm long, yellow to brown, not or slightly twisted anticlockwise. Calyptra plicate, usually sparsely hairy. Capsules immersed to emergent, erect, narrowly cylindric to urceolate, 1.3–2 mm long, straight, yellow, deeply 8-ribbed. Peristome double; exostome teeth 8, recurved; endostome segments 8. Operculum mamillate, c. 0.3 mm long.