丛本藓属

Plants slender, small to medium-sized, bright green to yellowish green, in dense tufts. Stems erect, simple, rarely monopodially branched, usually moderately tomentose at the base; in cross section rounded triangular; central strand weakly differentiated or absent; outer cortical cells small and thick-walled. Leaves densely arranged, erect, obliquely appressed or curved-contorted when dry, often lanceolate, oblong-lanceolate to ovate-lanceolate or ligulate, acute or gradually acuminate, usually twisted at the apex; margins flat or carinate, entire, sometimes crenulate to weakly rounded-denticulate at shoulder portion of the base; costa strong, ending at or near the apex, or shortly excurrent, strongly keeled, adaxial surface cells large, oblong, thick-walled, smooth; abaxial surface cells small, linear-rectangular, papillose, with 1 stereid band; upper leaf cells rounded-quadrate or rounded-hexagonal, firm-walled to thick-walled, with densely low, rounded, multi-papillae; basal cells somewhat differentiated, subquadrate to irregularly rectangular, firm- or thick-walled, yellowish green to hyaline, smooth. Dioicous; male and female inflorescences terminal on short lateral branches. Inner perichaetial leaves slightly longer than the stem leaves, broad-oblong, attenuate, sheathing at the base. Setae elongate, smooth, yellowish brown or reddish brown, more or less twisted; capsules erect, oblong-obovate to short-cylindrical; exothecial cells irregularly oblong; stomata phaneropore on neck, 4–8 per capsule; annuli absent or in one or two rows of weakly vesiculose cells; opercula obliquely long-rostrate; peristome teeth absent. Calyptrae cucullate, smooth. Spores spherical, yellowish brown, pluripapillose.

The genus Anoectangium consists of 56 species worldwide, with distribution mainly in warm and moist habitats of the tropics as well as in the arctic and mountains of the world. Five species are recognized in China.

Dixon (1924) placed this genus in the Orthotrichaceae. However, the growing habitats, the absence of creeping stems, the leaf shapes, and the capsule structure of Anoectangium all point to the Pottiaceae.

Lower Taxa

• Anoectangium aestivum (Hedw.) Mitt.
• Anoectangium clarum Mitt.
• Anoectangium crassinervium Mitt.
• Anoectangium stracheyanum Mitt.
• Anoectangium thomsonii Mitt.