Sphagnum perichaetiale

Detailed description

Plants usually robust, dirty yellowish or brownish-green, sometimes with a faint orange tinge, forming moist or water-logged cushions; capitulum not obscured by branches, with a small apical bud. Fascicles of 4 (rarely 2-3) branches, the spreading and pendent branches well differentiated. Stems less than 100 mm, partially obscured by pendent branches; cortical cells mostly in 3 layers, those of the outermost layer short (1-2:1), with 1 large pore at the upper end, and weakly developed fibrils, surrounding a woody, dark-brown to nearly black internal cylinder. Stem leaves erect or pendent, Ungulate and inrolled in upper third to half, c. 2 mm long, weakly bordered, hyaline cells not or sparsely divided, fibrillose, on abaxial surface with few (mostly 3-6) large, ringed pores which are often aggregated with those of adjacent cells to form pseudolacunae, and larger (owing to resorption) and more numerous in lower portion of leaf and near margins; on adaxial surface pores absent. Branches (spreading) c. 5-8 mm long; cortical cells in a single layer, fibrillose, ± uniform, eporose or singly pored. Branch leaves broadly ovate, concave with cucullate and rounded apices, c. 2.5 mm long (from middle of spreading branch), strongly roughened (cristate) at back near apex owing to cell wall resorption, serrulate above, bordered by a single row of narrow cells with a resorption furrow, with pores not clearly visible under stereoscope (x50). Hyaline cells ± sigmoid, mostly 150-180 x 36-45 microns (upper median), fibrillose, not divided, on abaxial surface with few (mostly 3-4) inconspicuous pores aggregated at adjacent corners in groups of 2-3, often forming pseudolacunae; on adaxial surface with a few (1-4) large, unringed pores scattered along commissures. Branch leaf cross-section with hyaline cells convex on both surfaces; green cells narrowly urceolate to elliptic, exposed equally on both surfaces; commissural walls smooth.