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.

leaves may be less fibrillose or efibrillose and less porose or aporose than the branch leaves, often septate, a distinct border of narrow linear chlorophyllous cells often along margins and at base, and with a greater width:length ratio than branch leaves in anisophyllous forms, partly differentiated in hemiisophyllous forms, and identical in isophyllous forms.

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

typically dimorphic as spreading and pendent branches, but some species lack branches or branches are not clearly differentiated, pendent branches typically more slender than spreading branches and with a tendency to adhere to and cover the stem.

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.

with 2/5 phyllotaxy, of a 1-stratose network of alternating chlorophyllous and hyaline cells;

hyaline cells usually S-shaped, rarely rhomboid, nearly always strengthened with conspicuous spiral fibrils, small to large, round to elliptic and sometimes ringed pores occur along commissures or rarely on cell lumen, convex surface typically with more pores per cell than concave surface; chlorophyllous cells may be enclosed on both surfaces, more broadly exposed on one surface or equally exposed on both surfaces as viewed in transverse section, adjacent cell walls typically smooth, but various types of cell wall projections may be clearly visible in transverse section.

dioicous.

dioicous or monoicous; stalked globose antheridia borne at the tips of branches usually with swollen colored tips of branches near capitulum; long-necked archegonia borne on short branches singly surrounded by perichaetial leaves that are typically longer than branch leaves.

with few pseudostomata.

spherical, brown to black, lacking an annulus or peristome with a operculum convex;

spore sac amphithecial in origin, over-arching columella.

membranous.

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

proximal laesura more than 0.5 spore radius.

tetrahedral, with prominent trilete mark, fine to coarse superficial surface, distal surface may have raised Y-mark, bifurcated Y-mark sculpture, or none.

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.

fascicles typically with 2 spreading and 1–2 pendent branches, but there may be up to 12(–14) per fascicle.;

branch stems typically green, with a superficial layer of inflated retort cells; these grouped or solitary, usually porose at the distal end with a conspicuous or inconspicuous neck.

typically 1-stratose, gametophyte developing from lateral margin.