Didymodon umbrosus

(Müller Hal.) R. H. Zander

Phytologia 41: 22. 1978,.

Basionym: Barbula umbrosa Müller Hal. Linnaea 42: 340. 1879
Synonyms: Didymodon australasiae var. umbrosus (Müller Hal.) R. H. Zander Trichostomopsis crispifolia (Müller Hal.) H. Robinson Trichostomopsis umbrosa
Treatment appears in FNA Volume 27. Treatment on page 547. Mentioned on page 539, 543, 548.

Plants usually green to very bright green distally, contrasting with light tan proximally. Stems to 1(–1.5) cm, central strand present. Stem leaves spreading-incurved and twisted to incurved-appressed when dry, spreading to spreading-recurved and not keeled when moist, monomorphic, long-lanceolate, broadly concave adaxially across leaf, usually 1–2.5(–4) mm, base sharply differentiated in shape, ovate, margins usually plane, entire, apex narrowly acute, 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 rectangular, 4–6 cells wide at mid leaf, guide cells in 1–2 layers; basal laminal cells strongly differentiated medially, rectangular, walls very thin or hyaline, often perforated by transverse slits; distal laminal cells in rather distinct rows, 7–12 wide, 1:1 or occasionally longitudinally elongate, papillae usually absent, lumens oval to rounded-quadrate or rounded-rectangular, walls convex on both sides of lamina, 2-stratose in one or more rows along margins. Specialized asexual reproduction by multicellular tubers on proximal rhizoids. Seta 0.7–1 cm. Capsule 1–1.9 mm; peristome teeth 32, linear, weakly twisted, to 600 µm. Spores 11–15 µm. Distal laminal KOH reaction variously negative or yellow- or orange- or red-brown.


Phenology: Capsules maturity not determined.
Habitat: Soil, lava, dolomite, cliff face, rock
Elevation: moderate to high elevations (200-1900 m)

Distribution

V27 784-distribution-map.gif

Calif., N.Mex., N.Y., Tex., Mexico, South America, Europe.

Discussion

Didymodon umbrosus is one of a number of mundivagant taxa whose distribution is associated with human activities (P. M. Eckel 1986). The proximal marginal cells are elongate and in distinctive rows. The transversely slit basal cells are distinctive in many specimens though also found in taxa of the Dicranaceae (R. H. Zander 1981b), some of which may belong in Pottiaceae (O. Werner et al. 2004).

Selected References

None.

Lower Taxa

None.
... more about "Didymodon umbrosus"
Richard H. Zander +
(Müller Hal.) R. H. Zander +
Barbula umbrosa +
Calif. +, N.Mex. +, N.Y. +, Tex. +, Mexico +, South America +  and Europe. +
moderate to high elevations (200-1900 m) +
Soil, lava, dolomite, cliff face, rock +
Capsules maturity not determined. +
Didymodon australasiae var. umbrosus +, Trichostomopsis crispifolia +  and Trichostomopsis umbrosa +
Didymodon umbrosus +
Didymodon +
species +