Family: Pottiaceae |
Plants: growing in loose turf or cushions, green distally, reddish brown proximally. Stems: ca. 0.5â1 cm; hyalodermis absent or weakly developed, not collapsed, sclerodermis absent or substereid, central strand present; axillary hairs of ca. 5 cells, proximal 1â2 cells occasionally somewhat thick-walled. Stem: leaves appressed or incurved when dry, spreading when moist; ovate to long-lanceolate, occasionally ligulate or spathulate, adaxial surface plane or broadly channeled across leaf, (0.5â)3â4(â7) mm; base not differentiated in shape or ovate and somewhat sheathing, proximal margins commonly bordered; distal margins plane, dentate distally or less commonly entire, bordered (sometimes intramarginally) by short-rectangular to elongate cells, usually less papillose, occasionally thick-walled, rarely 2â3-stratose; apex acute or rarely obtuse; costa percurrent or short-excurrent as flat, denticulate mucro, rarely ending 3â4 cells before apex, adaxial cells quadrate to short-rectangular, in 4â5 rows; transverse section round to elliptic, adaxial epidermis present, adaxial stereid band absent, guide cells 2â4 per layer in (1-)2 layers, hydroid strand present, usually large, abaxial stereid band present, of substereid cells, elliptic or round in section, abaxial epidermis present (occasionally only lateral) or absent; proximal cells differentiated across leaf, rectangular, 18â30 µm wide, (2â)4â6:1, walls of proximal cells thin; distal medial cells relatively large, quadrate to hexagonal or short-rectangular, ca. 18â24 µm wide, 1â2:1, often marginally elongate and multistratose; papillae hollow, simple to 2-fid, usually 6â8 or more per lumen, cell walls thin to evenly thickened, flat to weakly convex. Specialized: asexual reproduction absent. Sexual: condition autoicous, cladautoicous or dioicous. Perichaetia: terminal, leaves somewhat larger than the cauline leaves. Seta: 0.05â2.5 cm. Capsule: stegocarpous, theca ovate to cylindric, occasionally microstomous, 0.8â3.5 mm, annulus of 2â4 rows of vesiculose cells; operculum conic to rostrate, often narrowly so, occasionally systilius; peristome teeth absent, rudimentary or of 32 long, filamentous teeth, twisted counterclockwise, teeth when well developed to 1.5 mm. Calyptra: cucullate, occasionally flaring proximally and not split. Spores: 8â30 µm. KOH distal laminal color reaction red. Distribution: Nearly worldwide, most diverse in austral temperate areas.
Discussion: Species 20 (2 in the flora).
Hennediella was recently recognized as much larger than previously thought (T. L. Blockeel 1991; R. H. Zander 1989, 1993). The bordered, dentate, plane leaves with flat laminal cells, red in KOH, are distinctive. The sporophyte varies among the species from well developed to much reduced. The operculum is often long, (0.6â)1.2â1.8 mm. The genus is found in soil and on rock, commonly in wet areas.
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