Guerramontesia

Description

Plants small, growing in dense turfs, dark green. Stems usually simple; hyalodermis undifferentiated, sclerodermis absent, central strand usually undifferentiated; axillary hairs of seven to eight hyaline cells. Rhizoids brownish, smooth; rhizoidal gemmae absent. Leaves crispate when dry, patent to spreading when moist, lingulate to spathulate, usually slightly convex distally, flat proximally; base not differentiated; lamina unistratose, yellowish with KOH; apex usually rounded, not cucullate; margins plane, papillose-crenulate to slightly sinuose from near apex to below middle, unistratose, unbordered or border hardly differentiated; costa ending below the apex; ventral surface cells of the costa hexagonal to rectangular, papillose; dorsal surface cells of the costa linear, smooth or slightly papillose; in cross-section at midleaf elliptic to semicircular, in (1-)2-3 layers, band of ventral stereids undifferentiated, band of dorsal stereids semicircular to slightly lunulate, hydroids usually undeveloped, dorsal surface cells differentiated at lateral part by cells similar to those of the lamina, ventral surface cells quadrate to rectangular or oblate; upper and middle laminal cells quadrate-rounded to quadrate-hexagonal, rectangular or oblate, thin-walled, not collenchymatous, papillose, upper and middle marginal cells quadrate-hexagonal to oblate, slightly thick-walled, papillose; basal laminal cells rectangular, usually inflated, thin-walled, not collenchymatous, smooth, basal marginal cells rectangular, thin-walled, smooth. Autoicous. Perigonia occurring as small buds; perigonial leaves ovate. Perichaetia terminal; perichaetial leaves similar to the vegetative ones. Seta erect, twisted to the right in the upper part and slightly to the left in the lower part, yellowish brown to orange. Capsule exerted, straight, slightly sulcate; theca cylindric, orange to yellowish brown; exothecial cells rectangular, thin-walled; stomata at theca base, phaneroporous; annulus of 2 rows of vesiculose cells, revoluble; peristome of 16 variously cleft, occasionally perforate, coarsely papillose, straight teeth, orange to yellowish brown, basal membrane undifferentiated. Operculum conical to rostrate, not systylius, with straight cells, orange to yellowish brown. Calyptra cucullate, pale yellow, smooth. Spores spherical, light brown, papillose.