5. Sphagnum compactum de Cand. ex Lam. & P. de Cand. 密叶泥炭藓 mi-ye ni-tan xian
Fl. Franç., ed. 2, 2: 443. 1805. Type. Europe.
Sphagnum compactum var. imbricatum Warnst., Bot. Gaz. 15: 226. 1890.
Plants stout in dense or compact tufts, grayish to yellowish green or tinged with pinkish red. Stem cortex in 2–3 layers, hyaline cells large, thin-walled, without fibrils, with a single pore; central cylinder yellowish brown. Stem leaves 0.50–0.55 mm × 0.6 mm, triangular-ligulate, with rounded, involute, often lacerate apices; borders clearly widened at leaf base, occupying about 1/6 leaf width; hyaline cells rhomboidal, not divided, without fibrils, with pores only on the ventral surface. Branches short, stout, and crowded in fascicles of 4–6 with 2–3 spreading. Branch leaves 1.6–2.6 mm × 0.8–1.6 mm, broadly ovate, several times larger than stem leaves, concave with involute-concave apex; borders indistinct, sometimes denticulate along margins; hyaline cells densely fibrillose, with numerous pseudopores, 2–3 pores at the corners of each cell on the ventral surface, few to numerous rather larger pores at the ends on the dorsal surface; green cells in cross section small, narrowly oval to elliptic, centrally located or slightly widened toward the dorsal surface, enclosed by hyaline cells on both surfaces. Monoicous. Perigonial leaves not differentiated. Perichaetial leaves broadly ovate to oblong ovate, subsecund, concave. Spores yellowish brown, 32–35 µm in diameter.