40. Sphagnum squarrosum Crome, Samml. Deut. Laubm. 24. 1803.
Sphagnum cymbifolium var. squarrosum (Crome) Nees & Hornsch., Bryol. Germ. 1: 11. 1823. Sphagnum teres var. squarrosum (Crome) Warnst., Eur. Torfm. 121. 1881, nom. illeg.
Sphagnum squarrosum var. subsquarrosum Russ. ex Warnst., Hedwigia 27: 271. 1888.
Plants rather robust, jade green to yellowish green or yellowish brown, in loose tufts. Stem cortex in 2–4 layers, hyaline cells thin-walled, without fibrils, sometimes with large pores; central cylinder pale green or yellowish orange. Stem leaves 1.6–1.7 mm × 1.0–1.4 mm, large, ligulate, rounded obtuse, somewhat lacerate at the apex; borders narrow, indistinct; hyaline cells in the upper half broadly rhomboidal, often undivided, without fibrils and pores, sometimes divided, cells in the lower half narrowly rhomboidal, sometimes with the traces of fibrils, with large pores. Branches in fascicles of 4–5, with 2–3 spreading, stout. Branch leaves 2.0–2.3 mm × 1.0–1.2 mm, broadly ovate-lanceolate, concave, strongly squarrose and gradually narrowed to an involute-concave acumen from an erect base; margins involute, blunt and dentate at the apex; hyaline cells densely fibrillose, with small, ringed pores in the upper cells, half-elliptic pores at the opposite ends in the lower cells on the ventral surface, with a few pores at the upper corners in the upper cells, more and more pores at the opposite ends in the lower half on the dorsal surface; inner walls adjacent to green cells sometimes faintly papillose; green cells in cross section triangular to trapezoidal, exposed more broadly on the dorsal surface, also slightly exposed on the ventral surface. Dioicous; antheridial branches green; archegonial branches elongate. Perigonial leaves smaller than vegetative branch leaves. Perichaetia leaves large, broadly ligulate, concave. Spores yellowish, papillose, 22–25 µm in diameter.
Type. Germany: Mecklenburg.
Chinese specimens examined: HEILONGJIANG: Bo-li Co., Y.-L. Zhang 1450 (KUN), 2157 (KUN, MO); Dailing Pref., W. Wang 874, 930 (KUN); Da Xing An Ling (Greater Khingan Mt.), C. Gao 145, 13673 (KUN, IFSBH); S-R. Liu 745a (IFSBH, MO); Hong Xing Pref., T.-Y. Ding 830190 (KUN); Mu-ling Co., C. Gao 13671, 13663 (IFSBH, MO); Xiao Xing An Ling (Lesser Khingan Mt.), T. Cao 40303 (IFSBH, MO), P.-C. Chen & C. Gao 365 (KUN, MO), 621 (IFSBH, MO), C. Gao 8197 (MO), S.-E. Liu 598, 8907 (IFSBH, KUN), D.-Z. Wang 225 (KUN), Z. Wang 234, 1679 (KUN), Z.-H. Zhang 4120 (KUN), Y.-C. Zhu 6312, 6314 (KUN). JILIN: Changbai Shan (Mt.), C. Gao 1198, 7341 (IFSBH, KUN), K.-C. Lang 46, 53a (KUN), S.-E. Liu 229, 8747 (IFSBH, KUN). LIAONING: S.-E. Liu 7940 (KUN, MO), 1525 (KUN), T.-S. Liu 250 (KUN), R.-L. Zhao 557 (KUN), B.-C. Zhu 280, 282 (KUN). NEI MONGOL: Da Xing An Ling (Greater Khingan Mt.), P.-C. Chen & C. Gao 834 (IFSBH, KUN, MO), 990 (IFSBH, KUN), C. Gao 97 (IFSBH, MO), S.-E. Liu 8747 (KUN), H.-F. Xie 4, 40 (KUN). SICHUAN: Mu-ping Co., X.-Y. Hu 24, 28 (KUN, PE); Tian-quan Co., Z.-L. Wu 12367 (KUN, PE). YUNNAN: De-qin Co., M. Zang 76001 (KUN); Fu-gong Co., L.-S. Wang 82-512 (KUN), D.-C. Zhang 892 (KUN, MO); Gong-shan Co., M. Zang 469 (KUN, MO), 464, 888 (KUN), D.-C. Zhang 481, 647 (KUN); Teng-chong Co., L.-S. Wang 83-142 (KUN); Wei-xi Co., L.-S. Wang 364 (KUN), Q.-W. Wang 31296 (KUN, PE), Handel-Mazzetti 8494 (H, KUN).
Habitat: in seasonally flooded areas or on wet soil under conifers; sometimes on rotten wood in shade; Distribution: China, India, Korea, Japan, Central Asia, Europe, Greenland, North America, New Zealand, and North Africa.
This is a common species in northeastern and southwestern China. It is characterized by having rather robust and jade green plants that frequently produce sporophytes and by having large and squarrose branch leaves.
Illustrations: C. Gao (ed.) 1994 (Pl. 21, figs. 1–9).