Dicranoweisia Lindberg ex Milde, 1869.

Mosses included in Dicranoweisia have crispate leaves with entire margins and acute to acuminate apices. They make compact tufts or cushions on the substratum.

Key to Dicranoweisia

Our two California species of Dicranoweisia are easily determined simply on the basis of habitat. D. contermina is a plant of montane rock outcrops; D. cirrata is a plant of logs and coniferous tree bases at low elevations. Elsewhere in western North America, Dicranoweisia crispula poses problems. We would recognize, without strong conviction, two infraspecific categories of that widespread entity. In California however, we have not yet found typical material of D. crispula.

Species included in this key are in Seligeriaceae:
Dicranoweisia cirrata (Hedwig) Lindberg in Milde
Dicranoweisia contermina Renauld & Cardot
Dicranoweisia roellii Kindberg in Röll, not known from CA

A. Median and basal cells with cuticular papillosity; costa with substereids, and without clear definition of the guide cells; sporophytes immersed to slightly emergent .....Amphidium: various species
A. Cuticular papillosity absent or present as long streaks restricted to median leaf cells; costa with a strong abaxial stereid band; sporophytes exserted on a long seta .....B

B. Margins recurved near the base; cuticular papillosity lacking .....C
B. Margins plane to incurved; cuticular ridges present on median laminal cells .....D

C. Plant epiphytic and on logs and fenceposts, often at low elevations; juxtacostal, immediate supra-basal cells usually with very thick walls (lumen/wall ratio often greater than 1) .....Dicranoweisia cirrata
C. Plant on soil or rocks at high elevations; juxtacostal, supra-basal cells without such wall thickening .....Cynodontium: various species

D. Basal portions of peristome teeth striate; awn comprising about 1/3 of perichaetial leaf length; plant common in forests at mid elevations .....Dicranoweisia contermina
D. Peristome teeth papillose throughout; awn comprising about 1/2 of perichaetial leaf length; plant rare and local in alpine regions .....Dicranoweisia roellii not known from CA