Thalli prostrate, in compact cushions or patches, up to 3 or 4 mm thick, in several overlying layers of dense and intricately intertwined, slightly rounded, narrow bands, quite fleshy and firm, but rather brittle, bright green, with an ill-defined, somewhat darker, narrow strip occupying median 1/3 or more of branches: when dry, brown to dark brown. Main axis up to 15 mm long, not markedly differentiated though often retaining its dominance branching generally crowded or irregular-sometimes bifurcate, branches narrowing somewhat toward tips or maintaining same width throughout, rarely slightly dilated distally, apically ± truncate, shallowly notched, margins obtuse, not winged. Primary branches/pinnae arising laterally from axis, very close together or at intervals of 0.30-0.45 mm between successive ones, opposite or subopposite. obliquely spreading at angles up to 30° with axis, occasionally suberect, often relatively well developed, 3.5 mm long, up to 0.5 mm wide, usually linear, some bifurcate, rarely trifurcate, others poorly developed, almost rudimentary. Secondary branches/pinnules quite rare, if present, mostly remaining small. Stolons unbranched, generally arising on basal part of axis, occasionally developing more distally from apices of some primary branches. Dorsal epidermal cells in median part of apical segment of main axis from above 4-6-sided, thick-walled. 40-50 x 27.5-37.5 µm, subdorsal cells larger, 75-130 x 30.0-42.5 µm, subventral cells, 87.5 x 15-20 µm, ventral epidermal cells 35-60 x 30-40 µm. Oil bodies not seen in material studied. Margins of apical segment of main axis entire, front above outer cells 25.0-37.5 x 27.5-35.0 µm, subquadrate to rectangular, intramarginal cells 5-or 6-sided, 32.5-50.0 x 27.5-37.5 µm, walls somewhat thickened. Cross sections of main axis at ± middle of ultimate segment biconvex, ± 180 µm, or 6/7 cell layers up to 240 µm, or 8 cell layers thick medianly, and up to 460 µm wide, margins tapering to obtuse, dorsal epidermal cells 27.5-30.0 µm high, medullary cells ovoid to almost spherical, sizes variable, 25-15 x 22.5-35.0 µm, walls thickened, ventral epidermal cells 30-35 µm high: cross section of primary branch at ± its middle plano-convex, ± 200 µm or 5/6 cell layers thick medianly, up to 475 µm wide, medullary cell walls slightly thickened: cross section of stolon oval. ± 160 µm or 6 cell layers thick medianly, ± 210 µm wide, cell walls somewhat thickened. Mucilage papillae ventral, clustered at emarginated apex of pinnae and then in two. spaced, acropetal rows, one on either side or midline, reddish brown, club-shaped, 62.5-75.0 x 20-25 µm above, narrower below, rarely persistent. Rhizoids in widely scattered, irregular patches along ventral surface of pinnae, hyaline, up to 15 µm wide. Asexual reproduction by gemmae not seen. Dioicous. Antheridial branches solitary or occasionally in sympodial pairs, lateral on main axis opposite or subopposite primary branch, otherwise on primary branch close to its base, stipitate, ± oblong, up to 600 µm long, ± 320 µm wide, mostly bearing 3 or 4, rarely up to 8 pairs of antheridia. Cavities 70-100 µm diam., encircled by 2 or 3 rows of cells, 25-30 x 30 µm; in cross section ± 250 µm high, margins winged, with single, incurved row of large, obliquely orientated cells, 75.0-112.5 x 40-45 µm, apically rounded and free, otherwise adjoining; ventral papillae up to 30 µm long, in lateral pairs, but rare. Gynoecial branches short and obliquely ventro-lateral on main axis, opposite or at base of primary branch, ± sessile, not seen with archegonia. Only with very young calyptra, up to 500 µm long, including corona, the latter with apical row of radiating cells, width across widest part below 480-525 µm, including surrounding paraphyses, which are scale-like and dentate, with cells 40.0-52.5 x 27.5-30.0 µm. Calyptra clavate, up to 2.4 x 0.7 mm, cross section of wall ± 180 µm or 5/6 cell layers thick, some outermost ones with low protrusions, at apex corona smoothly rounded above, cells thick-walled, dislodged at maturity by emerging capsule. Seta ± 6.5 mm long, ± 280 µm wide, with 4 central and an outer row of 12 cells, i.e. 4 cells diam. Capsule ± ellipsoidal, 790-850 µm long, elaterophore internally attached to apex; valves 280-350 µm or 21-24 cell rows wide, cells of epidermal layer in external longitudinal view, 55-110 x 10.0-12.5 µm, with strong vertical (radial) thickenings, evident as nodular brown bulges; in cross section cells rectangular, ± 7.5 µm thick, thickenings on adaxial radial and abaxial radial walls extending slightly onto outer and inner tangential walls, resulting in a crescentic ring of thickening, bands on one side of median wall alternating with those on the other side in a mirror image; inner cells in internal longitudinal view 67.5-85.0 x 12.5-17.5 (-20.0) µm, with nodular thickenings and with faint semi annular bands; in cross section cells ± 10 µm thick, thickened on adaxial radial and abaxial radial walls, extending slightly onto outer tangential walls and further across inner tangential walls. Spores ± orbicular, 12.5-15.0 µm diam., translucent, scabrate. Elaters 97.5-317.5 x 7.5-10.0 µm, with single spiral band, tapering to unspiralled apical portions. Chromosome no.: n = unknown.
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