Dicranella palustris (Dickson) E. F. Warburg

Dicranella palustris is known by its squarrose-spreading, decurrent leaves ending in a narrow but rounded and crenulate tip. Lax, relatively large expressions of D. schreberiana, often given recognition as var. robusta, are smaller and have leaves with slender, acute tips, serrated margins, and broad cells. The New Hampshire and California reports were by A. J. Grout (1928-1940, vol. 1, as D. squarrosa) and D. H. Norris and J. R. Shevock (2004), respectively.

Plants relatively robust, 2-11 cm, in loose, light-green or yellow, ± shiny tufts. Leaves not crowded, 2.5-3 mm, abruptly narrowed to a narrow, squarrose limb from an erect, oblong or obovate base, subtubulose and generally ± twisted-crispate when dry, concave when moist, often cucullate at a rounded though often narrow apex, decurrent at base; margins erect, irregularly crenate at the extreme tip; costa subpercurrent, smooth abaxially; distal cells elongate, 4-9:1, the basal cells longer, yellow at the insertion, often ± differentiated at extreme basal angles. Sexual condition dioicous. Seta 10-30 mm, dark red. Capsule 1-1.5 mm, curved-inclined, smooth; annulus present or absent; operculum stoutly conic-rostrate; peristome teeth ca. 500-650 µm, divided about ¹/2 way distally, vertically papillose-striolate. Spores 16-25 µm, smooth or papillose.

Plants medium-sized to large, (1–)3–8 cm high, light to yellowish green, somewhat shiny, in deep, loose tufts. Stems erect or ascending, sparsely radiculose below, branched by innovations. Leaves squarrose or squarrose-recurved from an erect, oblong to obovate base, 2–3 mm long, subtubulose, more or less twisted when dry, concave when moist, gradually narrowed to a rounded or obtuse, cucullate apex, rarely acute at the apex; margins plane or somewhat undulate in the upper part, entire or irregularly crenulate at the apex, decurrent at base; costa slender, subpercurrent, smooth at back; upper cells short- to long-rectangular, 35–125 µm × 9–14 µm, thin-walled; lower cells becoming longer near the costa and insertion, shorter and wider near the alar region. Dioicous. Perichaetial leaves not much differentiated from the upper stem leaves. Setae straight, 1.5–1.8 cm long, dark reddish; capsules ca. 1.5 mm long, oblong-ovoid, inclined, curved and asymmetric, nearly smooth when dry; opercula stoutly short-rostrate, slightly curved, ca. 0.8 mm long; annuli absent or poorly developed, in 1 row of small cells; peristome teeth lanceolate, divided nearly to the middle, reddish. Spores ca. 25 µm in diameter, minutely roughened.

Distribution: China, Japan, Russia, Europe, and North America.

Habitat: on wet soil in seeps or near roadsides and open fields.

Bryum palustre Dickson, Fasc. Pl. Crypt. Brit. 4: 11. 1801; Dicranella squarrosa (Schrader) Schimper

Anisothecium palustre (Dicks.) I. Hagen, Kongel. Norske Vidensk. Selsk. Skr. (Trondheim) 1914(1): 35. 1915. Dicranum squarrosum Schrad., J. Bot. (Schrader) 1801(1): 68. 1803. Dicranella squarrosa (Schrad.) Schimp., Syn. Musc. Euro. 71. 1860. Anisothecium squarrosum (Schrad.) Lindb., Musci Scand. 26, 1879.

Dicranella palustris là một loài Rêu trong họ Dicranaceae. Loài này được (Dicks.) Crundw. mô tả khoa học đầu tiên năm 1962.