Flora of North America species comparison

leaves ovate-triangular to triangular, 1–1.6 mm; appressed to spreading;

apex acute to slightly obtuse;

hyaline cells often fibrillose and often 1-septate.

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.

straight and unranked, in capitulum tapering at distal end to a point, leaves greatly 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-lanceolate to lanceolate, 2–3.5 mm; straight, undulate and slightly recurved when dry;

margin serrulate;

hyaline cells on convex surface with 0–1 small pores at cell apex on concave surface with round wall thinnings in cell angles (often indistinct or lacking); chlorophyllous cells trapezoidal in transverse section and exposed more broadly on the convex surface.

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.

monoicous.

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.

26–40 µm; ± roughly to densely granulose.

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

stems green, 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.