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rusty beard moss

Habit Plants usually blackish green. Plants usually red-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 to spreading when dry, strongly recurved and keeled when moist, monomorphic, ovate-triangular to ovate-lanceolate, adaxially grooved along costa, 0.8–2 mm, base scarcely differentiated in shape to ovate, margins nearly plane to recurved at mid leaf, usually entire, apex broadly acute, not fragile;

costa percurrent to short-excurrent, weakly tapering and not much wider at the base, pad of cells absent, adaxial costal cells elongate, 2–4 cells wide at mid leaf, guide cells in 1 layer;

basal laminal cells little differentiated, quadrate or very short-rectangular, walls thickened;

distal laminal cells 11–15 µm wide, 1:1, papillae usually present, simple, often large and sharp, 1–3 centered over lumens, lumens angular, walls irregularly thickened, convex on both sides, 1-stratose.

Seta

0.7–1 cm.

0.6–1.2 cm.

Capsule

1–1.9 mm;

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

0.7–1.5 mm;

peristome teeth 16, linear, cleft to near base, nearly straight to twisted counterclockwise once, 275–600 µm.

Spores

11–15 µm.

7–9 µm.

Specialized

asexual reproduction by multicellular tubers on proximal rhizoids.

asexual reproduction specialized structures absent.

Distal

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

laminal KOH reaction red- or orange-brown.

Didymodon australasiae

Didymodon ferrugineus

Phenology Capsules mature winter–spring. Capsules mature winter–spring.
Habitat Soil, gypsum, acid rock, ledges, sandstone, silt Soil, ledges and outcrops, limestone, tundra, wet areas
Elevation moderate to high elevations (300-2000 m) (moderate to high elevations (1000-6600 ft)) low to moderate elevations (60-1400 m) (low to moderate elevations (200-4600 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
AK; AR; AZ; CO; IL; MI; MT; NC; NM; NY; VA; VT; WV; AB; BC; MB; NB; NL; NT; NU; ON; YT; Mexico; Central America; Asia; Greenland; Europe; West Indies; n Africa
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.)

The sporophyte of Didymodon ferrugineus is rare and similar to, but often smaller than, that of D. fallax. This species is easily mistaken for the western Triquetrella californica, which, however, is quickly distinguished by its triangular stem section, distal leaf margins sharply crenulate by projecting papillae (but not by projecting cell walls as in D. nigrescens), and distal medial laminal papillae tall, branching from the base, and centered over each lumen. It intergrades with D. fallax to some extent but is usually larger, with broader, ovate-lanceolate leaves that are commonly strongly reflexed (and therefore do not lie flat on a slide), and the papillae may be large and strongly evident. The leaf base is never abruptly ovate as it sometimes is in D. fallax. The peristome is very fragile and often appears missing.

The illegitimate name Tortula recurvifolia (Schimper) Austin has also been used for this species.

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

Source FNA vol. 27, p. 547. FNA vol. 27, p. 557.
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. 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
Synonyms Tortula australasiae, D. diaphanobasis, Husnotiella torquescens, Trichostomopsis australasiae, Trichostomopsis brevifolia, Trichostomopsis diaphanobasis, Trichostomopsis fayae Barbula ferruginea, Barbula reflexa, D. fallax var. reflexus, D. rigidicaulis
Name authority (Hooker & Greville) R. H. Zander: Phytologia 41: 21. (1978) (Schimper ex Bescherelle) M. O. Hill: J. Bryol. 11: 599. (1982)
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