Meteorium nigrescens (Sw. ex Hedw.) Dozy & Molk.

Authority

Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.

Family

Meteoriaceae

Scientific Name

Meteorium nigrescens (Sw. ex Hedw.) Dozy & Molk.

Description

Species Description - Plants relatively slender to medium-sized, in green (shade forms) to red-brown (sun forms), frequently black-tinged in older parts, stiff, often extensive colonies. Stems creeping or less often pendent, to ca. 20 cm long, irregularly to ± regularly pinnate, the branches often erect, often <1 cm long but rarely to 2.5 cm, not uncommonly naked, sometimes with flagellate branches, terete-foliate; in cross-section with 4-7 rows of small thick-walled cells surrounding larger thin- to firm-walled cells, central strand of very small thin-walled cells; pseudoparaphyllia foliose, with cells papillose; axillary hairs with 1-2 short brown (or occasionally hyaline) basal cells and 3-4(-5) short rounded hyaline distal cells, the distal cell wider than those below, in axils of caducous leaves the hairs with a single small short brown basal cell and a single oval (ca. 2:1) hyaline distal cell. Stem and branch leaves somewhat differentiated, the stem leaves larger, broader, longer acuminate and with a more pronounced cordate base, branch leaves erect-appressed when dry, sometimes spreading in shade forms, spreading to wide-spreading when moist, typically ovate-triangular but lanceolate in colonizing forms, 1.1-1.4 mm long, gradually short-to long-acuminate (but only rarely hairpointed), not or somewhat concave, shallowly plicate, with an expanded ± cordate base with cordate areas when well developed ± undulate, shortly decurrent; margins subentire or more commonly with projecting papillae, serrulate-crenulate near base, sometimes recurved for ca. 1/4 the leaf length and beginning just above midleaf; costa single, slender, ending near midleaf, not projecting at apex; cells rounded long-rhomboidal, 2-6:1, pluripapillose and prorulose with (1-)3-5(-7) papillae/cell, the papillae seemingly arranged randomly and not occurring only over the lumina, becoming longer in the acumen and juxtacostally, consistently short (ca. 2:1) toward the leaf base except marginally and juxtacostally, becoming smooth toward the insertion and in more extensive areas juxtacostally; alar cells differentiated in small areas, subquadrate, smooth, thin- to firm-walled. Asexual propagula frequent, of microphyllous flagellate branches arising from leaf axils and in extreme cases very abundant; caducous leaves common with all but proximal- and distal-most branch leaves caducous, leaving naked stems with small tufts of proximal leaves. Dioicous. Perichaetial leaves erect, lanceolate to oblong-lanceolate, ca. 2 mm long, long-acuminate; margins subentire to serrulate, plane; costa single, ending at midleaf or sometimes at base of the acumen; cells linear-flexuose, smooth, firm-to thick-walled, porose, becoming long-rectangular toward the insertion. Setae elongate, slightly roughened throughout, orange, 4-7 mm long, from a densely erect-hairy vaginula; capsules erect, symmetric, broadly cylindric, ca. 2 mm long, including a fairly conspicuous and well-developed neck ca. 0.5 mm long; exothecial cells subquadrate to short-rectangular, becoming firmer-walled and oblate in 3-5 rows at the mouth; annulus of 1 row of quadrate thick-walled cells, fragmenting; operculum obliquely long-rostrate, ca. 1.25 mm long, often pale at apex; exostome teeth on the front surface with prominent thick cell boundaries, papillose throughout, not trabeculate at back; endostome with a relatively low basal membrane ca. 4 cells high, segments finely papillose, linear, ± keeled, not perforate, ca. 3/4 the length of the teeth, cilia none or rudimentary (1-2 cells high). Spores spherical, finely papillose, 15-40 µm diam. Calyptrae cucullate, stiffly erect-hairy.

Discussion

3. Meteorium nigrescens (Hedw.) Dozy & Molk., Musci Frond. Ined. Archip. Ind. 160. 1848; Hypnum nigrescens [Sw.] Hedw., Sp. Musc. Frond. 250. 1801; Pterigynandrum nigrescens (Hedw.) Schwagr., Sp. Muse. Frond. Suppl. 3(1): 224. 1828; Papillaria nigrescens (Hedw.) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1875-76: 265. 1877; Tricholepis nigrescens (Hedw.) Grout, Moss FI. N. Amer. 3: 214. 1934. Pilotrichum funale Wilson, Ann. Mag. Nat. Hist. 20: 378. 1847; Neckera funalis (Wilson) Müll. Hal., Syn. Muse. Frond. 2: 136. 1850; Papillaria funalis (Wilson) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1875-76: 266. 1877; Pilotrichella funalis (Wilson) Paris, Index Bryol. 994. 1897. Papillaria nigrescens var. donnellii Austin, Musci Appalach. Suppl. 10. 1878; Papillaria nigrescens subsp. donnellii (Austin) Kindb., Canad. Rec. Sci. 6: 19. 1894; Tricholepis nigrescens var. donnellii (Austin) Grout, Moss Fl. N. Amer. 3: 214. 1934. Meteorium revolution Lindb., Moss. Dillen. Hist. Musc. 54. 1883. Papillaria haitensis H. A. Crum & Steere, Amer. Midl. Naturalist 60: 28. 1958. Discussion. Meteorium nigrescens is a very common lowland moss. The leaves are often black-tinged on the older parts of the stems. Asexual reproduction is common by means of caducous leaves (the so-called var. donnellii) and microphyllous flagellate branches. The leaves are mostly ovate-triangular and narrowly acuminate. However, they are almost never hairpointed. The cells are pluripapillose and mostly relatively short, ca. 26:1. The leaf base is cordate and the cells in this area are consistently short (ca. 2:1), rather than elongate as in M. deppei and M. pseudoteres. Papillaria haitensis (Plate 104, figures 10-16) was described on the basis of a single specimen, primarily distinguished on the basis of smooth leaf cells. However, the leaf shape and areolation are just those of M. nigrescens. Also, careful examination of the type found some leaves with unipapillose cells. Based on these circumstances, I am synonymizing the name here, until additional collections are available for re-evaluation.

Distribution

Range. United States (Florida, Alabama, Mississippi, Louisiana), Mexico to Panama, Venezuela and Colombia to Bolivia, northern Argentina, Paraguay, Brazil, Guyana, Surinam, Trinidad, reported from the Old World tropics (but not confirmed here); Bahamas (Abaco, New Providence), Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico, Nevis, Guadeloupe, Barbados; growing on trunks and branches of trees and shrubs, rocks (usually calcareous), and road banks, in mesic areas, from sea l

United States of America North America| Mexico North America| Central America| Venezuela South America| Colombia South America| Ecuador South America| Peru South America| Bolivia South America| Argentina South America| Paraguay South America| Brazil South America| Guyana South America| Suriname South America| Trinidad and Tobago South America| Bahamas South America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Puerto Rico South America| Saint Kitts and Nevis South America| Guadeloupe South America| Barbados South America|