Orthotrichum aucklandicum

Detailed description

Plants in small, blackish cushions, the tips often yellow-green to light-green. Stems erect, mostly 2-4× branched, rarely simple or once branched, c.3-12 mm high. Leaves loosely-erect and twisted, sometimes incurved when dry, loosely-erect and straight to erect-spreading when moist, 2.8-3.9 mm long, tri- or bistratose above, ligulate-lanceolate to narrowly ligulate from an ovate base, obtuse or sometimes acute; margins plane, often tristratose or quadristratose; costa ending just below the apex, in cross-section consisting of uniform stereids with no guide cells, in the upper portion of the leaf usually covered on the ventral side with larger cells, on the dorsal side usually not covered by lamina cells or if covered these often partially stereid in appearance; upper cells irregularly rounded to irregularly hexagonal, smooth; basal cells rectangular to elongate-rectangular, slightly nodose to costa, shorter towards margins. Autoicous, Perigonia often at ends of separate branches. Setae 0.5-1.1 mm long; capsules 0.8-1.2 mm long, ± 0.7 mm wide, oblong when dry, ovate to ovate-oblong when wet, gradually narrowed to the seta, immersed, the mouth positioned within the upper 2/3 of the leaf, usually constricted beneath the mouth when old and dry, smooth; exothecial cells rectangular, extremely thick-walled on the tangential side; stomates immersed in the lower ½ of the capsule; subsidiary cells strongly differentiated and completely covering the stomates; Peristome diplolepideous, single; exostome teeth 16, papillose, spreading-recurved when dry; endostome segments none; preperistome well-developed, sometimes up to ½ length of the exostome. Calyptrae conic, mitrate, strongly plicate, naked or with 1-2 multicellular hairs, with small papillae near apex. Spores multicellular, 40-70 µm, irregularly spherical to cubic-rectangular.