Family: Orthotrichaceae |
Plants: small to medium-sized, in tufts or loose cushions. Stems: erect or rarely creeping, branches erect to ascending. Leaves: straight and not crisped to flexuose and crisped when dry, erect-spreading to spreading-flexuose when moist, lanceolate, oblong-lanceolate, or linear-lanceolate, not rugose; margins entire; apex acuminate, acute, or narrowly obtuse; costa ending near apex or rarely excurrent; basal laminal cells rounded-quadrate to elongate-rectangular or linear; distal cells hexagonal-rounded to elliptic, 6–14 µm, sometimes smooth, usually papillose only over lumina, papillae 1 (or 2) per cell, conic, 2-fid, or clavate; marginal cells abruptly shorter than basal. Sexual: condition autoicous or rarely dioicous; perichaetial leaves larger than stem leaves. Seta: 1–10 mm. Capsule: fully exserted, fusiform-cylindric, ovate-oblong, or rarely obovate, slightly 8-plicate at mouth to strongly 8-ribbed entire length or rarely smooth, mouth puckered or capsule ± constricted below mouth; stomata superficial; peristome double or single; exostome teeth 8, sometimes split to 16, finely and densely papillose to papillose-striate or rarely smooth; endostome segments 8 or absent. Calyptra: mitrate, short- to oblong-conic, base usually deeply split several times, smooth, hairy, not plicate, covering 1/2 capsule. Spores: isosporous. North America, South America, Europe, Asia, Pacific Islands (New Zealand), Australia, temperate regions. Species ca. 60 (9 in the flora). Ecologically, Ulota is primarily found either in wet, shaded coniferous forests, particularly in areas of high rainfall, or in subalpine areas on small trees. Ulota is closely related to Orthotrichum. Ulota is distinguished from other genera by the conic calyptra, highly differentiated basal laminal cells, crisped leaves, superficial stomata, and lack of gemmae on the leaves. The leaf base is usually ovate and clasping the stem; the interior basal laminal cells radiate from the insertion and are thick-walled, often nodose, and usually orange; the capsule is gradually contracted to the seta with a long neck; the prostome is absent; the exostome teeth are more or less perforate at their apices; and the endostome segments are incurved. A few species show a close resemblance to Macromitrium in having creeping stems and similar basal cells and calyptrae. The North American species can be divided into four groups: dioicous species, producing gemmae (U. phyllantha); species with a single, erect-flexuose peristome and leaves not much crisped (U. coarctata and U. drummondii); species with a double peristome and exostome teeth reflexed (U. barclayi, U. crispa, U. curvifolia, U. hutchinsiae, and U. obtusiuscula); and species with creeping branched stems (U. megalospora). |