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3. Barbula Hedw., Sp. Musc. Frond. 1801.
扭口藓属
Plants small, slender to rather robust, green, yellowish green to yellowish brown or reddish brown, in loose or dense tufts, or forming cushions. Stems erect, simple or irregularly branched, often radiculose at base; central strand differentiated. Leaves appressed or contorted when dry, erect-spreading when moist, sometimes squarrose, ovate, ovate-lanceolate to linear-lanceolate, or narrow-ligulate to oblong-triangular, gradually acuminate to abruptly acute or rounded obtuse; margins entire, often recurved in lower 1/2–2/3 the leaf length; costa stout, percurrent to shortly excurrent, seldom short-awned, rarely ending below apex, in cross section often with two stereid bands; upper leaf cells small, usually rounded-hexagonal or quadrate to short-rectangular, rather thick-walled, obscure, unipapillose or multi-papillose, sometimes mammillose or occasionally smooth; basal cells usually differentiated, often larger, short-rectangular, smooth, hyaline. Gemmae sometimes developed, axillary on stalks or in leaf axils. Dioicous. Perichaetial leaves similar to stem leaves, but slightly larger and often sheathing at the base. Setae elongate, yellowish to sometimes reddish, smooth; capsules erect, rarely inclined, oblong-ovoid to long-cylindrical, rarely curved; annuli often differentiated; peristome teeth 32, slender, filiform, usually twisted counterclockwise, rarely straight, densely papillose; opercula conic, short- to long-rostrate. Calyptrae cucullate, smooth. Spores small, spherical, usually yellowish green, rarely light reddish brown, smooth or weakly papillose.
X.-J. Li (1996) united the genus Didymodon with Barbula. In this treatment we recognized both genera. Barbula consists of eight species from China. Barbula aquatica Card. & Thér. (Thériot 1906) reported from Guizhou (Prov. Kouy-Tchéou) cannot be verified.
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| 1 |
Leaves usually lanceolate, margins distinctly recurved; basal cells not clearly differentiated |
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(2) |
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Leaves usually ovate-lanceolate or lanceo-ligulate, margins mostly plane; basal cells differentiated |
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(3) |
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| 2 (1) |
Leaf apices rounded-obtuse or mucronate; costa dorsal surface coarsely papillose; peristome teeth erect |
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5 Barbula indica |
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Leaf apices acute to acuminate; costa dorsal surface smooth or only finely papillose; peristome teeth twisted |
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8 Barbula unguiculata |
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| 3 (1) |
Basal leaf cells not clearly differentiated; perichaetial leaves small, ovate-lanceolate, not sheathing at base |
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(4) |
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Basal leaf cells clearly differentiated, sometimes forming a V-shaped base; perichaetial leaves broadly ligulate, high sheathing at base |
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(5) |
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| 4 (3) |
Leaf apices usually rounded-obtuse, rarely acute at apex; costa ending below apex |
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4 Barbula dixoniana |
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Leaf apices usually acute or acuminate, rarely obtuse at apex; costa shortly excurrent as a mucro, rarely ending below apex |
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7 Barbula subcomosa |
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| 5 (3) |
Leaves shorter and broader, narrowly oblong-elliptic to narrowly ligulate; inner perichaetial leaves convolute, obtuse or acuminate at apex |
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(6) |
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Leaves long and narrow, ovate-lanceolate; inner perichaetial leaves not sheathing at base, not convolute, acuminate at apex |
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(7) |
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| 6 (5) |
Leaves bluntly acute, costa percurrent or ending just a few cells below apex; inner perichaetial leaves rounded-obtuse at apex |
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2 Barbula convoluta |
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Leaves acute to acuminate, costa shortly excurrent as an apiculus; inner perichaetial leaves acuminate at apex |
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3 Barbula coreensis |
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| 7 (5) |
Leaf margins undulate; upper leaf cells coarsely papillose on both surfaces; gemmae absent |
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1 Barbula chenia |
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Leaf margins plane; upper leaf cells finely papillose on both surfaces; gemmae common in leaf axils |
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6 Barbula propagulifera |
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Lower Taxa
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