The World Flora Online

Plants small to large. Stems pinnate or irregularly pinnate. Stem leaves falcate or sometimes straight, ovate-lanceolate, ovate, triangular-ovate, rounded-triangular, or broadly ovate, gradually narrowed to apex, concave, 0.9-5.1 × 0.4-1.6 mm; base erect to erectopatent, insertion slightly curved; margins entire or occasionally very finely denticulate; apex [obtuse] acute, or short- to long-acuminate, acumen gradually differentiated, in straight-leafed plants plane or at most weakly furrowed; costa single to mid leaf or beyond, ending well before apex; alar region transversely triangular, reaching from margin to costa or almost so; ratio of medial laminal cell length (µm) to leaf length (mm) 17.9-35.5 (very rarely to 38.2). Sexual condition dioicous.

Source: [
• 1
]. 

Plants relatively robust, in stiff to soft, ± lustrous, green to yellow-green, golden, or brown mats or tufts. Stems creeping, ascending to suberect, or floating, to 30 cm long, irregularly to pinnately branched ± in a single plane, the branches often curved; in cross-section without a hyalodermis, with (1-)2(-3) rows of small thick-walled golden cells (that strip off with the leaves on dissection) surrounding larger thin-walled cells, central strand small, of very small thin-walled cells; paraphyllia absent; pseudo-paraphyllia foliose; axillary hairs with 1-2 short brown basal cells and 1-2 elongate hyaline distal cells. Stem and branch leaves similar, crowded, erect to strongly falcate-secund throughout the leaf (i.e., not just in apical portions of leaves), ovate-lanceolate, the stem leaves to ca. 3.5 mm long, those of the branches to ca. 2.2 mm long, gradually acuminate to a flat or channeled acumen; margins entire or rarely subentire, plane to erect; costa single, ending 1/2-4/5 the leaf length; cells long-hexagonal to linear, 610:1, smooth, firm-walled and ± porose; alar cells usually abruptly differentiated in auriculate groups, not reaching the costa, enlarged, inflated, often with a single marginal row of narrow, short- to long-rectangular cells, the inner ones broader, rounded-rectangular, in (2-)3-4(-5) rows from top to bottom, in some leaves with only a few quadrate cells. Asexual propagula none. Dioicous. [Sporophytes unknown from the West Indies; the description based on European material.] Perichaetia enlarged, conspicuous; leaves erect, sheathing, oblong-lanceolate, to ca. 5.3 mm long, ± abruptly narrowly long-acuminate, subpiliferous, plicate; margins entire, plane to erect; costa single, ending near midleaf; cells linear, smooth, firm- to thick-walled, ± porose, becoming shorter, broader, rectangular, and laxer toward the insertion; alar cells not or slightly differentiated in extreme angles. Setae elongate, smooth, reddish, to ca. 6 cm long, twisted; capsules inclined, arcuate, asymmetric, cylindric, with a long neck, 2-2.8 mm long, only slightly constricted below the mouth when dry; exothecial cells rounded-quadrate to short-rectangular, firm-walled; annulus of (1-) 2-3(-4) rows of thick-walled large-lumened cells, deciduous; operculum conic-apiculate; exostome teeth yellow-brown, shouldered, strongly bordered, on the front surface cross-striolate below with overlying fine papillae, coarsely papillose above, trabeculate at back; endostome smooth, with a high basal membrane, segments ± narrow, keeled, narrowly perforate, cilia mostly paired, almost as long as the segments, very slender, nodulose. Spores spherical, finely papillose, 16-21 µm diam. Calyptrae cucullate, naked, smooth.

Source: [
• 2
]. 

1a. Drepanocladus aduncus var. aduncus   镰刀藓原变种   lian dao xian yuan bian zhong 

Source: [
• 4
]. 

Plants medium-sized to large; green, yellow green, or brownish green. Stem pinnately or irregularly pinnately branched; pseudoparaphyllia broad; axillary hairs with l-2(-3)-celled upper part, this hyaline when young. Stem leaves straight or usually ± falcate-secund (gradually curved), ovate-lanceolate or ovate or triangular-ovate or rounded-triangular or broadly ovate, narrowing gradually to apex, not plicate, concave; acumen in straight-leafed plants plane or at most weakly furrowed; apex (obtuse or) acute or short- to long-acuminate; margin entire or occasionally finely denticulate; costa single, ending in midleaf or above; median laminal cells (10.0-)20.0-197.5(-262.5) × (4.0-)4.5-11.0(-12.5) µm, unistratose, thin-walled and eporose to incrassate and porose, ratio "median leaf laminal cell length (µm)/leaf length (mm)" 17.9-35.5 (rarely to 38.2); alar cells inflated, hyaline; alar groups transverse-triangular, reaching or nearly reaching costa. Dioicous. Inner perichaetial leaves narrowing abruptly to acuminate apex. Exostome outside cross-striolate in lower part. [Sporophytes not known from neotropical material.]

Source: [
• 5
].