Chryso-hypnum diminutivum (Hampe) 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
Hypnaceae
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Scientific Name
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Description
Species Description - Plants small, in soft, dull, mostly pale- to dark-green, sometimes golden or brown-tinged, often extensive, dense mats. Stems creeping, to ca. 4 cm long, subpinnately branched, the branches mostly simple, short, blunt, densely foliate, somewhat complanate-foliate; in cross-section with 2-3 rows of small thick-walled cells surrounding larger thinner-walled cells, central strand small, of thin-walled nodulose cells; pseudoparaphyllia foliose; axillary hairs with a single brown basal cell and a single relatively short hyaline distal cell. Stem and branch leaves similar, stem leaves erect- to wide-spreading, ovate, 0.8-1.2 mm long, gradually and narrowly acuminate; margins serrulate ± throughout, plane; costa short and double, unequal, one fork often ending 1/3-1/2 the leaf length; cells linear, prorulose at upper and lower ends at back, firm-walled; alar cells small, quadrate to subquadrate in 6-12 rows in the extreme basal angles. Branch leaves usually wide-spreading, sometimes more imbricate, lanceolate to ovate-lanceolate, 0.6-0.9 mm long, gradually acuminate, concave; margins serrulate almost to base, plane; costa short and double, unequal, one fork often ending 1/4-1/2 the leaf length; cells linear to oblong-linear, conspicuously prorulose at upper and lower ends at back, firm-walled, becoming shorter and broader toward the insertion; alar cells small, quadrate to subquadrate in 4-10 rows in the extreme basal angles. Asexual propagula none. Autoicous. Perichaetial leaves erect, triangular-lanceolate, 0.75-1.4 mm long, gradually acuminate; margins serrulate above, entire below, plane; costa often short and double, well developed, sometimes absent; cells linear to linear-flexuose, smooth or low-prorulose at upper ends at back, firm-walled, becoming shorter, broader and thinner-walled toward the insertion; alar cells not differentiated. Setae elongate, smooth, reddish, 0.82.3 cm long, twisted; capsules horizontal to pendent, ± arcuate, somewhat asymmetric, ovoid to short-cylindric, 0.7-1.1 mm long, usually with a differentiated neck, constricted below the mouth when dry; exothecial cells quadrate to short-rectangular, the vertical walls firm, those of the crosswalls thin and wavy; annulus of 1-3 rows of elongate thick-walled cells, falling early; operculum conic-apiculate; exostome teeth shouldered, bordered, on the front surface cross-striolate below, coarsely papillose above, trabeculate at back; endostome with a high, smooth or obscurely roughened basal membrane, segments finely papillose, keeled, perforate, ca. as long as the teeth, cilia finely papillose, in groups of 1-2. Spores spherical, finely papillose, 11-19 µm diam. Calyptrae cucullate, naked or with a few hairs, smooth.
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Discussion
1. Chryso-hypnum diminutivum (Hampe) W. R. Buck, Brittonia 36: 182. 1984; Hypnum diminutivum Hampe, Linnaea 20: 86. 1847; Microthamnium diminutivum (Hampe) A. Jaeger, Ber. Thätigk. St. Gallischen Natur-wiss. Ges. 1876-77: 426. 1878; Mittenothamnium diminutivum (Hampe) E. Britton, Bryologist 17: 9. 1914; Ctenidium diminutivum (Hampe) M. Fleisch., Musci Buitenzorg 4: 1378. 1923. Plate 132, figures 1-8 Hypnum cubense Müll. Hal., Syn. Musc. Frond. 2: 267. 1851; Ectropothecium cubense (Mtill. Hal.) Mitt., J. Linn. Soc., Bot. 12: 514. 1869; Sigmatella cubensis (Müll. Hal.) Müll. Hal., Hedwigia 37: 259. 1898; Microthamnium cubense (Müll. Hal.) Müll. Hal., Hedwigia 37: 265. 1898; Mittenothamnium cubense (Müll. Hal.) Cardot, Rev. Bryol. 40: 21. 1913. Hypnum thelistegum Müll. Hal., Syn. Musc. Frond. 2: 269. 1851; Microthamnium thelistegium (Müll. Hal.) Mitt., J. Linn. Soc., Bot. 12: 504. 1869; Stereohypnum thelistegum (Müll. Hal.) M. Fleisch., Hedwigia 47: 290. 1908; Mittenothamnium thelistegum (Müll. Hal.) Cardot, Rev. Bryol. 40: 21. 1913; Rhizo-hypnum thelistegum (Müll. Hal.) Herzog, Biblioth. Bot. 87: 147. 1916. Hypnum thelistegum var. majus Sull., Proc. Amer. Acad. Arts 5: 289. 1861, nom. nud. Discussion. The often dense, soft mats of smallish, prostrate, subcomplanate-foliate plants with ovate leaves whose cells are prorulose at both upper and lower ends will readily distinguish Chryso-hypnum diminutivum. It is not at all like the species of Mittenothamnium with which it has been associated. In the Lesser Antilles it has been confused in aspect with Taxithelium pluripunctatum, but the seriately papillose laminal cells of this latter species makes microscopic distinction easy. Chryso-hypnum diminutivum is extremely common throughout the West Indies and northern South America at all but the highest elevations. Additional synonyms to those provided above are listed by Fleischer (1908) and Britton (1914). Surely many more await the ambitious monographer. Even the southern African C. patens Hampe is very similar to our species, but differs in the erect leaf margins, smaller spores, and hairier calyptrae.
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Distribution
Range. Southeastern United States (Florida and Alabama), Mexico, Central America, northern and central South America; Bahamas (Abaco, Grand Bahama, New Providence), Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Mona Island, Puerto Rico, Virgin Islands (St. John, St. Thomas), St. Martin, St. Eustatius, Nevis, Antigua, Guadeloupe, Martinique; a common lowland weed growing on a wide range of substrates, especially dead wood, in mesic forests, at all but the highest elevations.
United States of America North America| Mexico North America| Central America| South America| Bahamas South America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Virgin Islands South America| Puerto Rico South America| Saint Martin South America| Sint Eustatius South America| Saint Kitts and Nevis South America| Antigua and Barbuda South America| Guadeloupe South America| Martinique South America|