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didymodon moss, rough-leaf beard-moss, rough-leaf green-beard moss

Michigan beard moss

Habit Plants orange-green or red-brown, occasionally blackish. Plants green to glossy green.
Stem(s)

leaves appressed-incurved when dry, usually strongly recurved and keeled when moist, monomorphic, triangular to lanceolate, adaxially grooved along costa, 1.2–2.5 mm, base ovate, margins strongly and broadly recurved in proximal 1/2 or up to near apex, entire, apex narrowly to broadly acute, not fragile, commonly ending in a conical cell;

costa percurrent or ending 1–4 cells before the apex, tapering, widened pad of cells absent, adaxial costal cells quadrate to short-rectangular, 4–6 cells wide at mid leaf, guide cells in 1 layer;

basal laminal cells differentiated medially or across leaf, rectangular, walls usually thickened;

distal laminal cells 13–15 µm wide, 1:1, papillae usually absent, rarely simple, weak and domelike, 1 per lumen, lumens rounded or angular, walls thickened, often irregular or very weakly trigonous, weakly to strongly convex on both sides, 1-stratose.

leaves catenulate-incurved when dry, spreading and weakly keeled when moist, monomorphic, ovate-lanceolate, adaxially grooved in distal third, 0.9–1.1 mm, base often but not always sharply differentiated in shape, ovate, margins narrowly to broadly recurved in proximal 1/3–1/2, entire, apex narrowly acute, abruptly acuminate, not fragile;

costa percurrent to very shortly excurrent, tapering, widened pad of cells absent, adaxial costal cells elongate, 4 cells wide at mid leaf, guide cells in 1 layer;

basal laminal cells little differentiated, quadrate or very short-rectangular, walls thickened and lumens usually oval;

distal laminal cells 7–9(–12) µm wide, 1:1, papillae absent to low, simple, lumens subquadrate to oval, walls irregularly thickened, convex on both sides, 1-stratose.

Seta

0.4–0.6 cm.

Sexual condition

sterile in range of flora.

Capsule

ca. 1 mm;

peristome teeth 16, short-lanceolate to linear, irregularly cleft or perforate to near base, straight, to 50–300 µm. Spores 13–15 µm. Distal laminal KOH reaction red.

Specialized

asexual reproduction specialized structures absent.

asexual reproduction by multicellular spheric gemmae in leaf axils.

Sporophytes

not seen.

Distal

laminal KOH reaction yellow- or orange-brown.

Didymodon asperifolius

Didymodon maschalogena

Phenology Capsule maturity undetermined.
Habitat Calcareous or acid rock, moist calcareous soil, peatland, streamside, alpine Soil, rock, spray zone
Elevation moderate to high elevations (500-3700 m) (moderate to high elevations (1600-12100 ft)) low to high elevations
Distribution
from FNA
AK; CO; AB; BC; LB; NT; NU; YT; Greenland; Europe; Asia
from FNA
MI; BC; NT; Mexico; Greenland; Asia; Atlantic Islands (Cape Verde); Indian Ocean Islands (Reunion)
Discussion

Didymodon asperifolius can sometimes be immediately recognized by a red-yellow translucency in leaves of dry plants, like oiled paper. The adaxial surface of the costa may have either quadrate or short-rectangular cells. The distal laminal cells are also rather large for the genus. The KOH reaction, as well as the natural color of the lamina are sometimes light orange, but usually quite red. Some plants may appear green but the laminal cell walls are red under high magnification.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The significant characters of Didymodon maschalogena are the small size of the leaves, which are catenulate, and the presence of propagula; the appearance of the areolation cannot distinguish this species from many congeners but is clearly in longitudinal rows. The species is apparently widespread but of spotty distribution. It was long known as D. michiganensis, but J.-P. Frahm et al. (1996) recently found an earlier name.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 27, p. 560. FNA vol. 27, p. 558.
Parent taxa Pottiaceae > subfam. Barbuloideae > Didymodon Pottiaceae > subfam. Barbuloideae > Didymodon
Sibling taxa
D. anserinocapitatus, D. australasiae, D. bistratosus, D. brachyphyllus, D. eckeliae, D. fallax, D. ferrugineus, D. giganteus, D. johansenii, D. leskeoides, D. maschalogena, D. maximus, D. murrayae, D. nevadensis, D. nicholsonii, D. nigrescens, D. norrisii, D. perobtusus, D. revolutus, D. rigidulus, D. subandreaeoides, D. tectorum, D. tophaceus, D. umbrosus, D. vinealis
D. anserinocapitatus, D. asperifolius, D. australasiae, D. bistratosus, D. brachyphyllus, D. eckeliae, D. fallax, D. ferrugineus, D. giganteus, D. johansenii, D. leskeoides, D. maximus, D. murrayae, D. nevadensis, D. nicholsonii, D. nigrescens, D. norrisii, D. perobtusus, D. revolutus, D. rigidulus, D. subandreaeoides, D. tectorum, D. tophaceus, D. umbrosus, D. vinealis
Synonyms Barbula asperifolia, D. rufus Barbula maschalogena, Barbula michiganensis, D. michiganensis
Name authority (Mitten) H. A. Crum: Bryologist 67: 163. (1964) (Renauld & Cardot) Brotherus: in H. G. A. Engler and K. Prantl, Nat. Pflanzenfam. 234/235[I,3]: 1192. (1909)
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