Flora of North America species comparison

leaves channeled, concave, 1.1–1.8 mm;

apex sometimes incurved;

costa broadly channeled;

alar cells yellow, ± inflated at marginal insertion;

basal laminal cells 6–10 µm. Perichaetial leaves closely clasping seta, broadly lanceolate, to 2 mm, apex acute or acuminate, basal laminal cells rectangular, yellowish green.

erect-ascending and often 2-fid, or creeping, branches many, erect or ascending, simple or 2-fid;

outer cell walls thick, central strand absent, inner cells uniform, walls thin.

erect-appressed, crowded, spirally twisted, flexuose, crisped, or contorted when dry, erect-spreading to squarrose-recurved when moist, ovate-lanceolate, ligulate-oblong, or lanceolate-linear, ± channeled;

base not decurrent (decurrent in Zygodon);

margins usually plane to revolute, rarely involute to erect, entire or sometimes denticulate near apex;

apex rounded-obtuse, acute, occasionally acuminate, apiculate, or awned;

costa strong, ending near apex;

alar cells rarely differentiated;

basal laminal cells rectangular, elongate-linear, quadrate, rounded, or elliptic;

distal cells rounded-hexagonal, rarely rectangular, usually small, papillae 1–4(–6) per cell, conic or 2-fid, rarely smooth or mammillose, walls often incrassate.

dextrorse.

erect, dextrorse or sinistrorse, smooth or rarely rough.

usually gonioautoicous or dioicous, rarely pseudautoicous or cladautoicous;

perigonia terminal or lateral, sometimes occurring on dwarf male plants, budlike, large;

perichaetia terminal, further branching occurring by innovations, perichaetial leaves sometimes larger than stem leaves.

0.9–1.3 mm, sharply contracted to seta, neck absent;

exostome teeth 3–6 cells high, rudimentary, truncate.

erect, immersed, emergent, or exserted, ovate to cylindric-fusiform, symmetric, smooth or 8-ribbed, rarely 16-ribbed, sometimes constricted below mouth;

exothecial cells rectangular to elliptic, often differentiated into bands;

stomata superficial or immersed, usually below mid capsule, well developed;

annulus poorly developed or absent;

operculum convex to conic, rostrate;

peristome double, single, rudimentary or rarely absent;

prostome sometimes present, usually fragmentary;

exostome teeth 16, usually connate in 8 pairs, erect, recurved, or reflexed, lanceolate, thick, densely papillose or striate;

endostome segments 8 or 16 when present, hyaline, thin, linear-lanceolate, alternating with exostome teeth or connate to form rudimentary membrane, cilia absent.

mitrate or rarely cucullate, usually large and conspicuous, hairy or naked, plicate or not.

rounded-quadrate to elliptic-rectangular, 70–100 µm in longest dimension, almost smooth, brown.

isosporous or anisosporous.

asexual reproduction occasional, by gemmae.