12. Bellibarbula P. C. Chen, Hedwigia. 80: 222, plate 38. 1941.
[Latin bellus, beautiful, and genus Barbula]
Patricia M. Eckel
Plants in dense turfs, dull yellow-green to red-brown distally, brown or red-brown proximally. Stems small, erect, 0.6-3 cm; hyalodermis absent, sclerodermis thick, central strand present; axillary hairs short, 3-4 cells long, the basal 1(-2) cells yellow. Leaves incurved and weakly contorted when dry, weakly spreading when moist, short ovate-lanceolate to triangular; base little differentiated or ovate; margins strongly recurved in basal 3/4 or nearly throughout, entire, lamina 1-stratose; apex narrow and bluntly acute, sometimes acuminate, occasionally with an apiculus; costa ending before the apex to percurrent, adaxial outgrowths absent, sinuose beyond leaf middle, rather thick, adaxial cells quadrate in 3-4 rows, papillose; transverse section circular or somewhat flattened, adaxial epidermis differentiated, adaxial stereid band moderately developed, guide cells 4-5 in 1 layer, hydroid strand lacking, abaxial stereid band present, abaxial epidermal cells present, semicircular or semi-elliptic; basal cells weakly differentiated medially near the insertion, quadrate to subrectangular, 1(-3):1, walls somewhat thin to evenly thickened; distal laminal cells irregularly hexagonal-quadrate to oval or elliptical, 1:1, 1-stratose, with small, sharp, simple to 2-fid papillae, 4-6 per lumen, thin- to somewhat thick-walled, in section superficially flat to subconvex on both surfaces. Specialized asexual reproduction absent. Sexual condition dioicous; perigonia at stem apex or as subterminal buds; [perichaetia terminal, distinctive, leaves convolute-sheathing, long-rectangular with an apiculus, to 2 mm. Seta 4-6 mm. Capsule stegocarpous, theca cylindric, annulus of highly vesiculose cells, revoluble; operculum short-conic; peristome lacking. Calyptra cucullate. Spores 15-18 µm.] Laminal KOH color reaction red.
Species 2 (1 in the flora): e North America, Mexico, South America (Bolivia), Asia (China, the Himalayas, India).
Bellibarbula recurva has recently been removed from Bryoerythrophyllum. As originally described by Chen, Bellibarbula was separated from other genera in the Barbuleae by the ovate-lanceolate leaves, undifferentiated or scarcely differentiated leaf bases, papillose distal laminal cells, eperistomate capsule and convolute-sheathing perichaetial leaves. It is separable from Barbula by the color reaction to KOH of the distal laminal cells: yellow or orange in Barbula, red to brick-red in Bellibarbula. The sinuose costa in the distal part of the leaf differentiates Bellibarbula from Bryoerythrophyllum.