Flora of North America species comparison

green to dark brown, superficial cortex of 0–3 layers of efibrillose, non-ornamented, enlarged, thin-walled cells;

cells in outer layer aporose or with single round to elliptical wall thinning adjacent to the distal cell wall, visible only with heavy staining.;

stem leaves varying from smaller than to larger than branch leaves;

triangular, ovate to lingulate;

with rounded and sometimes erose apex;

border entire;

hyaline cells rhomboid to S-shaped, non-ornamented, efibrillose to fibrillose, aporose to sometimes porose, non- to multiply septate;

neither surface resorbed.

not always clearly dimorphic, spreading and pendent branches very similar.

usually of two distinctly different types;

branch leaves that are normally inrolled and broadest ca. 1/4–1/3 the distance from the base, more or less tapered to a cucullate to involute apex;

stem leaves more or less flat and usually broadest at the base;

both leaf types of a network of hyaline, dead cells and green chlorophyllose cells;

pores and reinforcing fibrils frequent in branch leaf hyaline cells and uncommon in stem leaf hyaline cells.

oval, ovate or ovate-lanceolate;

hyaline cells fibrillose, non-ornamented;

convex surface mostly with numerous elliptical to round pores (8–24 per cell) in rows along commissures on convex surface, concave surface with fewer or no pores; chlorophyllous cells elliptical in transverse section, ± equally exposed on both surfaces or slightly more on convex surface, end walls not thickened.

dioicous.

with few pseudostomata.

22–41 µm, with or without raised surface sculpture on distal surface;

proximal laesura more than 0.5 spore radius.

released by explosive opening of operculum.

fascicles 1–3 spreading and 0–2(–4) pendent.;

branch stems green, surrounded by 1 layer of efibrillose, non-ornamented, thin-walled, inflated cells, with solitary short-necked retort cells or with conspicuously necked retort cells, interspersed with primarily aporose rectangular-shaped cells.

thallose.

lacking.

consisting of a spherical capsule with pseudostomata on capsule surface, a very short seta, and a foot, exserted on a pseudopodium of gametophyte tissue.