Flora of North America species comparison

pale green to pale brown;

superficial cortex of weakly to moderately differentiated.;

stem leaves triangular-lingulate, 0.9–1.3 mm; usually appressed;

apex obtuse and often erose;

hyaline cells efibrillose and nonseptate.

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.

tapering or in more robust forms, frequently blunt, straight to arcuate, leaves slightly to moderately elongated at distal end.

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.

ovate to ovate-lanceolate; more than 1.8 mm; straight, stiff, not much undulate and reflexed to recurved;

margins entire;

hyaline cells on convex surface with a few end pores, but mostly numerous small to very small (often barely visible) pores or wall thinnings free from the commissures, on concave surface similar, but with pores generally fewer and larger; chlorophyllous cells triangular in transverse section, just reaching concave surface or slightly enclosed.

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.

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

spore sac amphithecial in origin, over-arching columella.

membranous.

18–27 µm;

both surfaces covered with rough, irregular verrucate plates of papillae, bifurcated Y-mark sculpture on distal surface;

proximal laesura less 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 with 2 spreading and 2 pendent branches.;

branch stems green, with cortex enlarged with conspicuous retort 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.