BFNA Title: Thamnobryum
XX. THAMNOBRYUM Nieuwland, Amer. Midl., Naturalist 5: 50. 1971 * [Greek thamnos, bush, shrub, alluding to the dendroid growth form]
Plants medium-sized to robust, dark green to yellow-green, slightly shiny to dull, dendroid, primary stem creeping, forming a stipe perpendicular to substrate, pinnate to sparsely branched distally. Pseudoparaphyllia foliose. Paraphyllia absent. Leaves of creeping stem appressed to erect-spreading, deltoid, acute; margins entire; costa single; distal medial cells irregularly rhomboidal to rectangular. Stipe leaves appressed to erect-spreading, deltoid, 0.5--1 mm, gradually becoming ovate where the stem branches, acute to broadly obtuse; margin entire; costa single; distal medial cells linear, smooth to slightly prorulose, pitted to unpitted at base. Stem leaves erect to erect-spreading, concave, ovate, broadly acute to obtuse; margins serrate at apex, entire proximally; costa strong, subpercurrent, 1--5 teeth along top 1/4 of costa; apical cells hexagonal, rhombic to rhomboidal, distal medial cells and basal cells linear to rectangular, smooth to prorulose, pitted or unpitted. Branch leaves concave, oblong-ovate to ovate, broadly acute, acute to acuminate; apical cells rhomboidal to elongate-rhomboidal, distal medial and basal cells rectangular. Inner perichaetial leaves erect to erect-spreading, oblong tapering into a subula, 1.5--2 mm, acute; margins entire; costa single, slender, ± reaching 1/2 of the lamina; apical cells rhomboidal, distal medial cells linear to rectangular, basal cells rectangular, pitted. Sexual condition synoicous, autoicous or dioicous. Seta reddish brown, 1 cm. Capsule horizontal, cylindric; exostome teeth striate at base, becoming striate with overlying papillae, papillose at apex, trabeculate; endostome from a high basal membrane, papillose, perforate, cilia present. Spores ca. 10 \um.
Species 42 (2 in the flora): North America, Mexico, West Indies, Central America, South America, Europe, Asia, Africa, and Australia.
Thamnobryum is distinguished from other dendroid mosses in the flora by the stout costa, and branches mostly hanging, not upright as in Climacium.
REFERENCE Norris, D. H. and J. R. Shevock. 2004. Contributions toward a
1. Branch leaves ovate, 1.5--2 x 0.5--0.6 mm, acute, coarsely serrate at apex, apical cells elongate rhombic, more than 2:1 1. Thamnobryum alleghaniense
2. Branch leaves oblong-ovate to ovate, 1--2.2 x 0.5--0.8 mm, obtuse to broadly acute, serrate at apex, apical cells subquadrate to short-rhombic, less than 2:1 2. Thamnobryum neckeroides
1. Thamnobryum alleghaniense (Müller Hal.) Nieuwland, Amer. Midl. Nat. 5: 51. 1917
Hypnum alleghaniense Müller Hal., Syn. Musc. Frond. 2: 502. 1851
Plants (3--)5--8(--10) cm, when dry rather incurved. Stem leaves 2--3.5 x ca. 1.4 mm. Branch leaves ovate, 1.5--2 x 0.5--0.6 mm; acute to acuminate; margin coarsely serrate; apical cells elongate rhombic, 3--5 x ca. 1.5 \um ; medial cells near costa short-rhomboid, longest axis 45° to costa, 3--4.5 x 1.5--2 \um, basal cells rectangular 6--10 x 1--2 \um. Sexual condition synoicous or autoicous.
Mostly rock or logs; commonly deeply shaded wet rock ledges, limestone cliffs, sandstone of Hemlock hardwood forests, mixed deciduous forest; 500--1500 m; N.B., N.S., Ont., Que.; Ala., Ark., Conn., Ga., Ill., Ind., Ky., Maine, Md., Mass., Mo., N. H., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va., W.Va., Wis.; Europe; Asia (China).
Thamnobryum alleghaniense is distinguished by the apical cells of the branch leaves which are elongate- rhombic and the longest axis of median cells near the costa is oriented at a 45° angle.
2. Thamnobryum neckeroides (Hooker)
Hypnum neckeroides Hooker, Musci. Exot. 1: 58. 1818
Plants (4--)6--8(--10.5) cm. Stem leaves 2--3.2 x 1--1.7 mm. Branch leaves oblong-ovate to ovate, 1--2.2 x 0.5--0.8 mm; apex obtuse to broadly acute; margins serrate at apex; apical cells subquadrate to shortly rhomboidal, 2--4 x 1.5--2 \um, median cells near costa long-rhomboid, longest axis parallel to costa, 3.5--5 x 1.5--2.5 \um, basal cells rectangular 5--8 x 1--2 \um. Sexual condition dioicous.
Rocks, humus, base of trees, mostly on shaded banks, boulders or cliffs; moderate elevations; B.C.; Alaska, Calif., Conn., Idaho, Mont., N. C., N. Y., Ohio, Oreg., Pa., Wash.; Europe (Czech Republic, Germany, Italy); Asia.
Thamnobryum neckeroides is distinguished by the distinctly concave, almost boat shaped branch leaves, and the rounded to broadly rounded apex. The apical laminal cells are mostly subquadrate to short-rhomboidal and the medial cells, next to the costa, have their longest axis parallel to the costa.
SELECTED REFERENCE Mastracci, M. 2003. Thamnobryum neckeroides (Bryopsida: Neckeraceae) lectotypification, synonymies, diagnostic characters, habitat, and distribution. J. Bryol. 25: 115--120.