2. Sphagnum angustifolium (C. Jens. ex Russ.) C. Jens. in Tolf 小叶泥炭藓 xiao-ye ni-tan xian
Bih. Kongl. Svenska Vetensk.-Akad. Handl. 16, Afd. 3(9): 46. 1891. Sphagnum recurvum ssp. angustifolium C. Jens. ex Russ., Sitzungsber. Naturf.-Ges. Dorpat 9: 112. 1890. Type. Europe.
Plants small, green to yellowish brown; capitula often small, not distinct radiate. Stem cortex in 1 layer, sometimes not well developed, hyaline cells lacking fibrils; central cylinder yellowish green. Stem leaves 0.5–0.8 mm × 0.5–0.7 mm, flat, nearly equilateral-triangular, slightly dentate or erose at a broadly acute apex; borders differentiated, slightly widened at the base; hyaline cells lacking fibrils, only divided at leaf base, generally without pores. Branch leaves ca. 1.1–1.4 mm × 0.3–0.4 mm, lanceolate, crowded and imbricate, spirally arranged when moist, not or only slightly undulate when dry, dentate and truncate at the apex; green cells in cross section triangular, exposed on the dorsal surface, slightly reaching the ventral surface; hyaline cells with large pores at the upper ends and a few small pores at the corners and along commissures on the dorsal surface, those from pendent branch leaves with numerous pores on the ventral surface. Dioicous. Sporophytes not seen.