The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

didymodon moss

Habit Plants usually blackish green. Plants usually green-, red- or dark brown.
Stem(s)

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-incurved when dry, weakly spreading and not keeled when moist, monomorphic, ovate-lanceolate, broadly concave adaxially across leaf, usually 0.7–1.2 mm, base weakly differentiated in shape, ovate, margins weakly recurved at mid leaf, minutely crenulate, apex rounded-acute, often weakly cucullate;

costa ending (2–)4–6 cells below the apex, not strongly spurred, little tapering, without an adaxial pad of cells, adaxial costal cells quadrate or short- to long-rectangular, 2 cells wide at mid leaf often grading to 4 proximally, guide cells in 1 layer;

basal laminal cells differentiated medially, walls thin or thick, quadrate to rectangular, not perforated;

distal laminal cells 9–11 wide, 1:1, papillae absent visible or low, simple, 1 over each lumen, lumens subquadrate to irregular, walls evenly thickened, weakly convex on both sides of lamina, 1-stratose.

Seta

0.7–1 cm.

Sexual condition

only perichaetial plants seen.

Capsule

1–1.9 mm;

peristome teeth 32, linear, weakly twisted, to 600 µm, occasionally rudimentary.

Spores

11–15 µm.

Specialized

asexual reproduction by multicellular tubers on proximal rhizoids.

asexual reproduction by mostly unicellular gemmae in leaf axils.

Distal

laminal KOH reaction variously negative or yellow- or orange- or red-brown.

laminal KOH reaction red.

Sporophytes

unknown.

Didymodon australasiae

Didymodon perobtusus

Phenology Capsules mature winter–spring.
Habitat Soil, gypsum, acid rock, ledges, sandstone, silt Calcareous rock or soil, bluffs, often near waterfalls
Elevation moderate to high elevations (300-2000 m) (moderate to high elevations (1000-6600 ft)) low to high elevations (100-3000 m) (low to high elevations (300-9800 ft))
Distribution
from FNA
AZ; CA; CO; NM; NV; OR; TX; Mexico; Central America; South America; Europe; n Africa; s Africa; Pacific Islands (New Zealand); Australia
from FNA
NT; YT; e Asia
Discussion

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 perobtusus is an extremely rare species known in the flora area from only two stations: Northwest Territories, Mackenzie District, Nahanni National Park, Virginia Falls, Scotter 22433 (NY); and Yukon, Firth River basin, near mouth of Mancha Creek, 68°40’N, 141°W, Sharp MC-58152a pro parte, 1958 (NY). It has several characters in common with D. revolutus of the southwestern United States and Mexico, including leaf and laminal papillae shape and unicellular gemmae borne in dense axillary clusters; however, D. revolutus differs by the strongly recurved to revolute margins, leaf cells with thin, light yellow walls, and gemmiferous plants uncommon, the propagula all unicellular. Both North American collections seen were from stations at which D. subandreaeoides is also present, growing in separate or occasionally confluent cushions. The taxonomic position of D. perobtusus is not clear. It is here placed near D. subandreaeoides because of dark, reddish color and similarity of areolation and laminal papillae. It may, however, turn out to be related to D. tophaceus, with which it has a certain resemblance.

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

Source FNA vol. 27, p. 547. FNA vol. 27, p. 549.
Parent taxa Pottiaceae > subfam. Barbuloideae > Didymodon Pottiaceae > subfam. Barbuloideae > Didymodon
Sibling taxa
D. anserinocapitatus, D. asperifolius, 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. maschalogena, D. maximus, D. murrayae, D. nevadensis, D. nicholsonii, D. nigrescens, D. norrisii, D. revolutus, D. rigidulus, D. subandreaeoides, D. tectorum, D. tophaceus, D. umbrosus, D. vinealis
Synonyms Tortula australasiae, D. diaphanobasis, Husnotiella torquescens, Trichostomopsis australasiae, Trichostomopsis brevifolia, Trichostomopsis diaphanobasis, Trichostomopsis fayae Barbula perobtusa
Name authority (Hooker & Greville) R. H. Zander: Phytologia 41: 21. (1978) Brotherus: Rev. Bryol. 56: 1. (1928)
Web links