Difference between revisions of "Polytrichastrum sexangulare var. sexangulare"

Revision as of 21:50, 16 December 2019

Plants small to medium, in loose tufts. Stems with cortical cells thin-walled. Leaves loosely to densely imbricate, erect-incurved at the tips, often ± secund, obtusely cucullate; sheath broadly elliptic, contracted to the blade; marginal lamina 2–6 cells wide, slightly broader and inflexed in the distal part of blade; perichaetial leaves similar to the foliage leaves. Seta straight. Capsule (4–)5–6-angled to terete; short-cylindric to ovoid to subglobose; peristome teeth 50–64, slender, of uniform size.

Habitat: Damp gravelly soil and rocks, snowbed communities and beside snow-melt streams
Elevation: moderate to high elevations

Greenland, Alta., B.C., Nfld. and Labr., N.W.T., Nunavut, Que., Yukon, Alaska, Mont., Utah, Wash., Wyo., Europe, Asia (Japan, Russia in s Siberia), Atlantic Islands (Iceland).

Discussion

In Nunavut, var. sexangulare is known from Baffin Island. Even when sterile, it can usually be recognized by secund, tubulose leaves with an obtusely cucullate apex. Polytrichastrum alpinum var. septentrionale is similar, but has papillose lamellae, and the leaf apex is not cucullate.

Selected References

None.

Lower Taxa