12. Sphagnum fuscum (Schimp.) Klinggr. 锈色泥炭藓 xiu-se ni-tan xian
Schriften Königl. Phys.-Ökon Ges. Köningsberg 13(1): 4. 1872. Sphagnum acutifolium Schrad. var. fuscum Schimp., Mém. Acad. Sci. Sav. Inst. Fr. 15: 64. 1857. S. acutifolium ssp. fuscum (Schimp.) Herib., Mém. Acad. Sci. Clermont-ferrand, sér. 2, 14: 444. 1899. Type. Europe.
Plants slender, up to 12 cm high, dark green tinged with brownish color, in compact tufts. Stem cortex in 3–4 layers, hyaline cells thin-walled, without fibrils; central cylinder brownish green or yellowish. Stem leaves 0.8–1.2 mm × 0.5–0.8 mm, slightly larger than or equal to branch leaves, oblong-ligulate, flat, with obtuse, entire or lacerate apex, borders narrow above the middle, suddenly widened below (ca. 1/4 the leaf width at base); hyaline cells divided, generally without fibrils. Branches in fascicles of 3–4, with 2 spreading. Branch leaves 0.8–1.3 mm × 0.4–0.5 mm, ovate-lanceolate, gradually narrowed to a blunt, dentate apex, borders narrowly differentiated, entire, involute above; hyaline cells fibrillose, with several rather large, ringed pores nearly along commissure on the dorsal surface, in the upper cells without pores on the ventral surface, with a few large pores below the middle parts of leaves; green cells often triangular or sometimes trapezoidal, exposed on the ventral surface, enclosed by hyaline cells on the dorsal surface. Dioicous; antheridial branches similar to vegetative branches, yellowish brown. Perigonial leaves small, broadly ovate. Perichaetial leaves large, broadly elliptic. Spores yellowish, smooth, 25–30 µm in diameter.