Rhynchostegiella (Schimp.) Limpr. (1896: 207)

Guerra, Juan, Ríos, Diana & Gallego, María Teresa, 2014, A revision of the genus Rhynchostegiella (Brachytheciaceae) in the Iberian Peninsula and Balearic Islands, Phytotaxa 183 (3), pp. 193-200 : 194

Rhynchostegiella (Schimp.) Limpr. (1896: 207) . Type:— Rhynchostegiella tenella (Dicks.) Limpr. (1896: 209) .

Plants small or minute, in lax or dense mats, yellowish green to deep green or blackish, often lustrous. Stems creeping or postrate, irregularly branched, sometimes irregularly pinnate; cross section circular, central strand present or absent, 1–2(3) stratose sclerodermis, hyalodermis none. Branches prostrate to semi–erect, occasionally slightly curved. Axillary hairs 2–3 celled, with 1–2 short basal cells and 1 rectangular hyaline distal cell, sometimes slightly brownish. Paraphyllia none. Pseudoparaphyllia foliose, triangular or rounded. Rhizoids arranged in fascicles or scattered on stems, brownish, smooth. Stem leaves usually appressed when dry, erect to erectopatent when moist, narrowly lanceolate to lanceolate–triangular, oval–lanceolate or oblong–lanceolate, concave to flat; lamina unistratose; apex acuminate, acute, sometimes obtuse; margins entire, sometimes denticulate near basal portion and apex, plane, rarely recurved; base not or sometimes slightly decurrent; costa single, rarely bifurcate to apex, ending at midleaf to percurrent, without spine; cross section rounded to biconvex or plane-convex towards the middle of the leaf; with 1 row of 2–5 guide cells and 1–2 dorsal stereid rows. Upper and mid-lamina cells long rhomboidal to vermicular, sometimes sinuous, rarely firm-walled, not porose, smooth; basal cells usually shorter and wider, weakly thick-walled, without porose walls; alar cells usually not differentiated or a few cells in leaf corner short–rectangular to quadrate or isodiametric, sometimes slightly opaque. Branch leaves similar to stem leaves or smaller. Asexual propagula absent. Autoicous. Perigonia gemmate, on stems; perigonial leaves oval–lanceolate to oblong, acute, short–acuminate. Perichaetia lateral; perichaetial leaves triangular to widely oval–lanceolate, with apex gradually long–acuminate, sometimes abruptly, with or without costa. Seta 1 per perichaetium, erect, straight or weakly sinuose, twisted, usually brownish to reddish or orange, papillose to smooth. Capsule stegocarpous, exerted, erect to horizontal, usually inclined, brownish; urn ovate, ellipsoid, short–cylindric to ovate–oblong, straight to weakly curved, neck barely differentiated. Exothecial cells rectangular to oblong–rectangular, firm–walled; stomata in capsule base. Annulus of 2–3 rows of cells, separating by fragments. Peristome double; exostome of 16 teeth, lanceolate, reddish brown to reddish, yellowish or orange, on outer surface cross-striolate with strioles papillose in basal tooth portion, papillose in upper third, strongly so at apex, inner surface trabeculate; endostome segments triangular–lanceolate, very narrowly perforated in midline, yellowish to brownish, sparsely papillose, cilia 1–2, long, sometimes filiform, usually fused, papillose, weakly nodulose, basal membrane high. Operculum usually long rostrate. Calyptra cucullate, smooth. Spores spherical to weakly ovoid, greenish to brownish, finely papillose.