39. Sphagnum sericeum C. Müll., Bot. Zeitung. 5: 481. 1847.
Sphagnum holleanum Dozy & Molk., Natuurk. Verh. Kon. Akad. Wetensch. Amsterdam 2: 6. 1854.
Sphagnum seriolum C. Müll., Flora 70: 421. 1887.
Plants bright green, tinged with yellow, silky lustre when dry. Stem cortex in 2–3 layers, hyaline cells thick-walled, yellowish, outer walls without pores, inner walls sometimes with small pores; central cylinder deep yellowish, stout. Stem leaves ca. 1.1 mm × 0.7 mm, nearly isosceles-triangular, acuminate and often apiculate at the apex, margins bordered by linear cells, evenly differentiated throughout; hyaline cells linear-rhomboidal, often 1–2 divided, without fibrils, with pores at the upper ends on the dorsal surface. Branches in fascicles of 5–6, with 2–3 spreading, slender, soft, or drooping, ca. 3 cm long. Branch leaves 1.0–1.4 mm × 0.4–0.5 mm, erect-spreading, loosely imbricate, ovate, concave, abruptly acuminate, sharp-pointed, margins involute, serrate, borders narrowly differentiated; hyaline cells larger near the base, smaller in the upper half, sometimes divided, without fibrils, nearly all green cells near the apex, with a single, rather large pore at the upper corner in each cell on the dorsal surface; green cells in cross section trapezoidal, tinged with yellowish, thick-walled, exposed more broadly on the ventral surface, also slightly exposed on the dorsal surface. Monoicous. Sporophytes not seen.
Type. Indonesia: Sumatra, Junghuhn s.n.
Chinese specimens examined: TAIWAN: Tai-pei Co., Suzuki 666 (KUN, TAI). YUNNAN: Bi-jiang Co., M. Zang 5816(b) (KUN).
Habitat: on wet ground under forests; Distribution: China, Indonesia, Malaysia, the Philippines, and New Guinea.
The characteristics of this species are: 1) plants with silky color; 2) stem leaves and branch leaves with apiculate apices; 3) the hyaline cells of stem leaves and branch leaves without fibrils; and 4) predominantly distributed in tropical Asia. Warnstorf (1890) considered this species close to Sphagnum cuspidatum, but the latter differs in having widened marginal borders near leaf base, having fibrils in hyaline cells and the green cells exposed more broadly on the dorsal surface, and in having its distribution in northern temperate regions.
Illustrations: Pl. 10, figs. 1–12.