Brachythecium ruderale (Brid.) W.R.Buck
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Authority
Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
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Family
Brachytheciaceae
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Scientific Name
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Description
Species Description - Plants rather slender, in ± lustrous, often soft, pale- to yellow-green, often dense mats. Stems creeping, mostly to ca. 10 cm long, irregularly but freely branched to subpinnately branched, the branches of a single stem often all the same length, usually <1 cm long; in cross-section with 2-4 rows of small thick-walled cells surrounding larger thin-walled cells, central strand well defined, of small thin-walled cells; pseudoparaphyllia foliose; axillary hairs with a single short hyaline or brown basal cell and 1-3 elongate hyaline distal cells. Stem and branch leaves slightly differentiated with stem leaves with a broader insertion, relatively broader and more pronounced decurrencies, branch leaves crowded, erect to erect-spreading when dry, spreading to wide-spreading when moist, lanceolate, 1-1.3 mm long, gradually and slenderly acuminate, the apex sometimes with a half twist, ± concave, mostly with a single, median plica, often obscuring the costa, rarely nonplicate, scarcely to somewhat decurrent; margins serrulate throughout, plane to erect to narrowly and irregularly recurved; costa single, ending 1/2-2/3, the leaf length, or occasionally short and double, often obscured by the strong, median plica; cells linear, straight, smooth, thin- to firm-walled, not or scarcely porose, becoming shorter and ± short-rectangular toward the insertion, a single row along the insertion sometimes ± inflated; alar cells confined to basal angles, only rarely reaching the costa, quadrate to short-rectangular. Asexual propagula none. Dioicous. Perichaetia inconspicuous; leaves spreading from an erect base, oblong-lanceolate, 1.1-1.9 mm long, gradually or more commonly abruptly slenderly long-acuminate; margins subentire, plane; costa none; cells linear, smooth, firm- to thick-walled, ± porose, becoming rectangular and lax toward the insertion; alar cells not differentiated. Setae elongate, smooth, reddish, 1.5-2.2 cm long, straight, slightly twisted; capsules inclined to horizontal, asymmetric, cylindric, 22.5 mm long, dark-brown; exothecial cells rectangular, thick-walled, becoming quadrate to ± isodiametric toward the mouth, stomata round-pored; annulus of 2-3 rows of small ± quadrate thick-walled cells, smaller than those of the exothecium; operculum high-conic; exostome teeth reddish brown, triangular, scarcely shouldered, strongly bordered, on the front surface cross-striolate below, coarsely papillose above, trabeculate at back; endostome with a high, smooth basal membrane, segments finely papillose, keeled, narrowly perforate below, becoming split down the middle and spreading above with age, as long as the teeth, cilia mostly in pairs, finely papillose, nodose to appendiculate, shorter than or as long as the segments. Spores spherical to oval, finely papillose, 14-18 µm diam. Calyptrae cucullate, naked, smooth.
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Discussion
1. . Brachythecium ruderale (Brid.) W. R. Buck, comb. nov.; Hypnum ruderale Brid., Muscol. Recent. Suppl. 2: 158. 1812; Stereodon ruderalis (Brid.) Brid., Bryol. Univ. 2: 824. 1827, comb. inval.; Stereophyllum ruderale (Brid.) Mitt., J. Linn. Soc., Bot. 12: 543. 1869. Plate 94, figures 7-14 ? Hypnum viridulum Brid., Muscol. Recent. Suppl. 2: 181. 1812; Hypnum ruderale var. viridulum (Brid.) Brid., Muscol. Recent. Suppl. 4: 168. 1819; Hypnum ruderale var. tenellum Brid., Bryol. Univ. 2: 586. 1827, nom. illeg.; Stereodon ruderalis var. tenellus (Brid.) Brid., Bryol. Univ. 2: 824. 1827, comb, inval. Hypnum implicatum Hornsch. ex Müll. Hal., Syn. Musv. Frond. 2: 362. 1851; Brachythecium implicatum (Müll. Hal.) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1876-77: 322. 1878. Brachythecium stereopoma Spruce, Cat. Muse. 20. 1867, nom. nud.; Hypnum stereopoma Spruce ex Mitt., J. Linn. Soc., Bot. 12: 561. 1869; Brachythecium stereopoma (Mitt.) A. Jaeger, Ber. Thátigk. St. Gallischen Naturwiss. Ges. 1876-77: 327. 1878; Chamberlainia stereopoma (Mitt.) H. Rob., Bryologist 65: 105. 1962. Brachythecium pseudo-laetum Mtill. Hal. ex A. Jaeger, Ber. Thátigk. St. Gallischen Naturwiss. Ges. 187677: 321. 1878, nom. nud., Müll. Hal., Hedwigia 37: 260. 1898. Brachythecium jamaicense Mtill. Hal., Bull. Herb. Bois-sier 5: 567. 1897. ? Brachythecium jamaicense var. albidum Müll. Hal., Bull. Herb. Boissier 5: 567. 1897. Cryptoneuron acuminatum Thér. & P. de la Varde in Thér., Rev. Bryol. Lichénol. 14(Trav. Bryol. déd. Husnot 2): 23. 1944. Discussion. Brachythecium ruderale is recognized by its slender size, leaves with long, slender acumina, and a median fold often obscuring the costa. It most resembles the northern B. oxycladon (Brid.) A. Jaeger but is more slender with a narrower acumen. Brachythecium ruderale, long known as B. stereopoma, is by far the most common species of Brachythecium in the West Indies. Indeed, at times it is even weedy, colonizing roadsides under grasses. It is easily recognized by its macroscopic appearance. The leaves are disposed in such a way that the branches and stems are often catenulate. The lanceolate branch leaves with a conspicuous median plica obscuring the costa prompted Thériot (1944) to describe Cryptoneuron and to relate it to Ptychodium. However, collections rarely can be found with nonplicate leaves but otherwise identical to typical material. The type of Brachythecium jamaicense var. albidum was not found. The destroyed holotype in Geheeb’s herbarium (B) was collected by H. Boswell in Jamaica. Duplicates were not located at BM, MANCH, or OXF. I previously used the name B. implicatum (Buck, 1993) for the species but have subsequently decided that Hypnum ruderale is indeed this species, and not B. rotaeanum De Not. (cf. Ireland & Buck, 1994: 10).
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Distribution
Range. Southwestern United States (Texas, New Mexico), Mexico through Central America, Colombia and Venezuela south to Argentina, Paraguay, Uruguay, southeastern Brazil, eastern and southern Africa; Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico; growing on soil, rock, bases of trees, etc., often in exposed areas, most common above 1000 m, but also extending into suitable habitats at much lower elevations, then usually growing on rock, often limestone.
United States of America North America| Mexico North America| Central America| South America| Africa| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Puerto Rico South America|