Didymodon australasiae
Didymodon norrisii
Norris' beard moss
leaves spreading-incurved and twisted to incurved-appressed when dry, spreading to spreading-recurved and not keeled when moist, monomorphic, short-lanceolate or sometimes short-ovate to long-elliptic, broadly concave adaxially across leaf, usually 1–2.5 mm, base scarcely differentiated in shape to ovate, margins usually recurved at mid leaf, entire, apex broadly acute or occasionally narrowly so, not fragile;
costa percurrent or ending a few cells below the apex, broader at mid leaf, occasionally weakly spurred, with a low adaxial pad of cells, adaxial costal cells quadrate, 4–6 cells wide at mid leaf, guide cells in 1–2 layers;
basal laminal cells differentiated medially or across leaf, quadrate to short-rectangular, walls very thin and not perforated;
distal laminal cells 7–12 wide, 1:1 or occasionally transversely elongate below, papillae usually distinct, low or simple to 2-fid, occasionally absent, lumens oval to rounded-quadrate, walls thin to evenly thickened, convex on both sides of lamina, 2-stratose in one or more rows along margins.
leaves appressed when dry, spreading and not keeled when moist, monomorphic; ovate to ovate-lanceolate, adaxial surface broadly concave across leaf and sometimes narrowly channeled near apex, 1.2–1.5 mm;
base weakly differentiated in shape, broadly ovate, sheathing at insertion;
margins recurved in lower 2/3–3/4, minutely crenulate by projecting cell walls;
apex acute to short-acuminate, occasionally broken off;
costa percurrent, strong, often weakly spurred, without an adaxial pad of cells or this weakly developed, adaxial cells quadrate from apex to near insertion, in 6-10 rows, guide cells in 2 layers;
basal laminal cells not differentiated or of 2–5 rows of slightly larger cells, walls of basal cells evenly thickened, quadrate to short-rectangular;
distal laminal cells 9–13 mm wide, 1:1(–2), often transversely elongate near proximal leaf margins, papillae of 2–4 hemispherical salients per cell or essentially absent and cells appearing broadly mammillose, lumens rounded-quadrate to ovate, walls evenly thickened and convex on both sides of lamina.
0.7–1 cm.
1.
1–1.9 mm;
peristome teeth 32, linear, weakly twisted, to 600 µm, occasionally rudimentary.
1.5–2 mm;
peristome teeth apparently absent or rudimentary.
11–15 µm.
10–13 µm.
asexual reproduction by multicellular tubers on proximal rhizoids.
asexual reproduction by fragile foliose stem tips.
laminal KOH reaction variously negative or yellow- or orange- or red-brown.
laminal KOH reaction deep brick or rose red.
–1.4 cm.
Didymodon australasiae
Didymodon norrisii
In North American Didymodon, hydroids are found in the costae of D. anserinocapitatus, D. australasiae, D. nevadensis, D. norrisii, D. umbrosus, D. revolutus, and D. vinealis, and in these species the adaxial stereid band is usually absent in well developed specimens. Intergrades exist between D. australasiae and D. umbrosus, but the extreme forms are common and quite distinctive.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Didymodon norrisii is known only from four localities—California, one station each in Oregon and coastal British Columbia—and is quite distinctive. In addition to the characters given in the description, the leaves are reflexed above a very short-sheathing basal collar, the abaxial cells are quadrate in distal 4/5 of leaf, the costal transverse section is rounded-elliptical, the adaxial stereid band is absent, and there are 5–6 guide cells (4 in an abaxial layer and 1–2 in a second, adaxial layer). Sporophytes are uncommon, and the short-conic operculum is of cells in nearly straight rows.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CalFlora
WildflowerSearch
iNaturalist
USDA Plants Database
BC
PNW Herbaria
