吕宋泥炭藓

Sphagnum densirameum Dix., J. Siam Soc. Nat. Hist. Suppl. 9: 4. 1932. Sphagnum luzonense var. macrophyllum Warnst., Sphagn. Univ. 398. 1911. Sphagnum luzonense var. sordidum Warnst., Sphagn. Univ. 398. 1911.

Plants rather small to medium-sized, to 5 cm high, yellow to brown, in loose or compact tufts. Stem cortex in 1 layer, hyaline cells large, thin-walled, without fibrils, with 1–2 large pores here and there; central cylinder orange. Stem leaves ca. 1.5 mm × ca. 1.0 mm, ovate-triangular, narrower at base, rounded-obtuse, margins involute to cucullate at the apex; hyaline cells densely fibrillose, with large pores on both surfaces, also with numerous small, ringed pores at the opposite ends along commissural rows on the ventral surface. Branches in fascicles of 3, with 2 spreading. Branch leaves 1.1–2.0 mm × 0.7–1.0 mm, ovate-lanceolate, margins slightly involute, secund and cucullate at the apex; hyaline cells densely fibrillose, with pores at the opposite ends along commissural rows on both surfaces, similar to the stem leaves, fibrils sometimes indistinct in the upper cells; green cells in cross section narrowly trapezoidal, thick-walled, exposed on both surfaces, more broadly to the dorsal surface. Dioicous. Sporophytes not seen.

Type. The Philippines: Luzon, Loher 1047.

Chinese specimens examined: YUNNAN: Wei-xi Co., Handel-Mazzetti 8495 (H, KUN).

Habitat: in bogs or on wet ground under forests; Distribution: China, Thailand, Vietnam, and the Philippines.

This species is similar to Sphagnum subsecundum, but it differs in having smaller plants (up to 5 cm high), hyaline cells of branch leaves with commissural pores on the ventral surface, and in having the green cells exposed more broadly on the dorsal surface. In contrast, S. subsecundum has larger plants (5–20 cm high), hyaline cells of branch leaves without commissural pores on the ventral surface, and centrally located green cells.

Illustrations: Pl. 8, figs. 1–3; Eddy (1977, Fig. 8, A–H).