Scopelophila ligulata Spruce 1881

The blackened proximal leaves and nearly isodiametric distal laminal cells help separate Scopelophila ligulata from Tortula. Leaf blackening, possibly associated with iron in the soil, also occurs in the common species Barbula unguiculata, which, however, has lanceolate leaves. Two variants are weakly distinguishable, a “hydric” form with a loosely pulvinate habit and flaccid, spreading leaves with the distal laminal cells thin-walled and the enlarged basal cells often extending beyond mid leaf, and a “montane” form with a densely pulvinate habit and narrow, firm, appressed leaves with the distal laminal cells mostly thick-walled and the enlarged basal cells mostly confined to the proximal third of the leaf (R. H. Zander 1967).

Plants medium-sized to rather large, to 5 cm high, soft, yellowish green to dark brown, in dense tufts. Stems erect, fragile, simple or branched, radiculose at the base. Leaves moderately contorted-curved when dry, spreading when moist, 2–3(–4) mm long, ligulate to elliptic-lanceolate from a narrowed base, obtuse to rounded apiculate at the apex; margins plane or somewhat recurved below, subentire to crenulate above, sometimes bordered by several rows of thicker-walled cells; costa slender, subpercurrent, ending a few cells below the apex; upper leaf cells quadrate to irregularly hexagonal, 5–8 µm in diameter, moderately thick-walled, smooth; basal cells laxly rectangular, somewhat enlarged, thin-walled, smooth. Setae ca. 5 mm long; capsules oblong-ovoid; opercula conic-rostrate, with a short erect beak.

Stems with sparse brown rhizoids. Cauline leaves brownish black proximally; margins usually bordered by thick-walled cells; apex obtuse to acute; costa with 1 layer of parenchymatous cells adaxial to the stereid band. Sporophytes not seen in area of the flora.

Distribution: China, Japan, India, Indonesia, the Philippines, northern Africa, Europe, and North and South America.

Habitat: on wet rocks in shade or soil walls.

Merceya ligulata (Spruce) Schimp., Syn. Musc. Eur. (ed 2) 2: 852. 1876. Merceya thermalis Fleisch. ex Broth., Nat. Pflanzenfam. (ed. 2) 11: 247. 1925, nom. illeg. Merceya thermalis var. compacta Fleisch. in P.-C. Chen, Hedwigia 80: 271. 1941, nom. nud.

Encalypta ligulata Spruce, Musci Pyren., no. 331. 1847; Merceya ligulata (Spruce) Schimper