Flora of North America species comparison

leaves lingulate-triangular to lingulate, 1–1.4 mm, apex broadly rounded but becoming acute in hemiisophyllous forms, border strongly developed at base (more than 0.25 width);

hyaline cells rhombic and 0–3-septate with some cells in leaf midregion 2–septate.

green to red-brown; 2–3 superficial cortical layers.;

stem leaves shorter than branch leaves, ovate-lingulate to oblong-lingulate, 1.6–1.8 × 1–1.2 mm;

hyaline cells mostly nonseptate.

weakly to strongly 5-ranked.

long and tapering with distinct squarrose spreading leaves, often terete in tundra forms.

ovate to ovate-lanceolate, 0.9–1.2 mm, concave, subsecund on some branches, apex involute;

hyaline cells on convex surface with numerous round to elliptic pores along the commissures, grading from small round pores near apex to round pores near base, on concave surface with large round pores in proximal portions of leaf.

larger than stem leaves, 1.9–2.8 mm, conspicuously squarrose from ovate-hastate base and abruptly narrowed 1/2–1/3 distance from apex into involute-concave acumen, often terete in tundra forms;

hyaline cells convex on both surfaces, non-ringed pores at ends and corners of cells, ringed pores on concave surface (4–8/cell) and nonringed pores (2–4/cell) on convex surface, internal commissural walls smooth or indistinctly papillose, chlorophyllous cells ovate triangular with widest part at or close to the convex surface.

dioicous.

monoicous.

18–33 µm, coarsely papillose on both surfaces;

proximal laesura less than 0.4 spore radius.

17–30 µm;

proximal surface finely papillose, distal surface smooth with raised bifurcated Y-mark sculpture;

proximal laesura more than 0.5 spore radius.

fascicles with 2 spreading and 1–2 pendent branches.

fascicles with 2 spreading and 2–3 pendent branches.;

branch stems with 1–2 layers of cortical cells.