裂齿藓

Dichodontium verrucosum Card., Bull. Herb. Boissier sér. 2, 7: 712. 1907.

Plants variable in size, usually 1–4(–8) cm high, dull, yellowish green to dark green or brownish below, in loose or compact tufts. Stems often branched, often with slender, subapical innovations, sparsely radiculose below, sometimes with small, subglobose, ovoid to ellipsoidal propagula on short branched filaments along the stem. Leaves oblong-lanceolate to ligulate, 1–3(–4) mm long, erect-spreading with incurved, variously contorted to twisted apices when dry, widely spreading to somewhat squarrose when moist, acute to rounded-obtuse at the apex; margins often recurved below, somewhat undulate above, irregularly dentate in the upper part, nearly entire below the middle; costa subpercurrent, usually projecting on the back in the upper part of leaves, with 4–5 large, guide cells in the middle row, dorsal stereid band better developed than the ventral band in transverse section; upper laminal cells irregularly quadrate to subquadrate, 8–12 µm wide, obscure, the marginal teeth noticeably pellucid, mammillose to conic-papillose on both surfaces; lower cells rectangular, rather pellucid, smooth; alar cells not differentiated. Dioicous. Perichaetial leaves not much differentiated from vegetative leaves. Setae erect, 6–20 mm long, yellowish; capsules oblong-ovoid, ca. 1.5 mm long, suberect to curved or inclined, smooth, not strumose; opercula erect to obliquely long-rostrate, almost as long as the urn; annuli absent; peristome teeth dark reddish, divided about halfway down, vertically striate below, papillose above, basal membrane extending 2–3 rows of cells above the mouth. Spores 14–20 µm in diameter, minutely papillose.

Type. Austria.

Chinese specimens examined: NEI MONGOL: Da Xing An Ling (Greater Khingan Mt.), E.-Z. Bai 3718, 3728, 4002, 4056 (HIMC). YUNNAN: Salwin, Handel-Mazzetti 9062 (H).

Habitat: on wet rocks in forests; Distribution: China, Pakistan, Japan, Russia (Siberia), Europe, and North America.

Illustrations: C. Gao (ed.) 1994 (Pl. 96, figs. 1–20).