Orthostichella pentasticha (Brid.) W.R.Buck

  • Authority

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

  • Family

    Lembophyllaceae

  • Scientific Name

    Orthostichella pentasticha (Brid.) W.R.Buck

  • Description

    Species Description - Plants medium-sized, slender, in pendent, ± lustrous, bright-to yellow-green, usually dense colonies. Stems creeping to pendent, to ca. 40 cm long, but locally usually ca. 10 cm, freely branched, in young material often ± pinnate, the branches seemingly indeterminate and capable of becoming stems; in cross-section with 3-5 rows of small thick-walled cells surrounding larger firm-walled cells, central strand none; paraphyllia absent; pseudoparaphyllia broadly foliose, the apex broadly obtuse and bluntly toothed; axillary hairs with 1(-2) short brown basal cells and (2-)3(-4) long-rectangular hyaline distal cells. Stem and branch leaves scarcely differentiated, conspicuously seriately ranked, erect-spreading to spreading, from the insertion, obovate to oblong-obovate, 1.3-1.6 mm long (stem leaves not appreciably longer), cuspidate, concave above, ± cordate at base; margins serrulate almost throughout, broadly incurved above, mostly plane below; costa none or short and single and ending below 1/4 the leaf length; cells long-hexagonal, ca. 10:1, to ca. 60 µm long, smooth, ± thin-to firm-walled, not at all porose, often becoming somewhat shorter near base of the cusp; alar cells gradually differentiated, few, subquadrate to short-rectangular, extending up the margins in 3-4 rows and across the insertion by (6-)8-10 rows but not approaching the costa, often yellow across the entire insertion. Asexual propagula none but leaves often caducous and leaving extensive areas of branches naked. Dioicous. [Sporophytes unknown from the West Indies; description based on Mexican material.] Perichaetia conspicuous, on branches; leaves differentiated, convolute, the vaginular hairs well included, oblong-lanceolate, 2-2.5 mm long, gradually short-acuminate; margins serrulate almost to base, plane; costa short and single; cells linear-flexuose, smooth, firm-walled, ± porose; alar cells not differentiated. Setae short, ± roughened above, yellowish, 3-4 mm long, curved; capsules exserted, erect, symmetric, short-cylindric, 1.1-1.4 mm long; exothecial cells subquadrate, thick-walled, becoming smaller and oblate toward the mouth; annulus ? none but in Brazilian material similar to that of O. hexasticha; operculum obliquely rostrate; exostome teeth linear-triangular, pale, not or scarcely shouldered, not or narrowly bordered, on the front surface papillose throughout, slightly trabeculate at back; endostome with a low basal membrane, segments papillose, keeled, narrowly perforate, cilia rudimentary or none. Spores spherical, finely papillose, 14-20 µm diam. Calyptrae not seen.

  • Discussion

    2. Orthostichella pentasticha (Brid.) W. R. Buck, Bryologist 97: 435. 1994; Hypnum pentastichum Brid., Muscol. Recent. 2(2): 100. 1801; lsothecium pentastichum (Brid.) Brid., Bryol. Univ. 2: 378. 1827; Pilotrichella pentasticha (Brid.) Wijk & Margad., Taxon 9: 52. 1960; Pseudopilotrichum pentastichum (Brid.) W. R. Buck & B. H. Allen in W. R. Buck, J. Hattori Bot. Lab. 75: 70. 1994. Plate 91, figures 9-17 Neckera rigida Müll. Hal., Syn. Musc. Frond. 2: 126. 1850; Meteorium rigidum (Müll. Hal.) Mitt., J. Linn. Soc., Bot. 12: 439. 1869; Pilotrichella rigida (Müll. Hal.) Besch., Mém. Soc. Sci. Nat. Cherbourg 16: 222. 1872. Neckera viridis Müll. Hal., Syn. Musc. Frond. 2: 125. 1850; Meteorium viride (Müll. Hal.) Mitt., J. Linn. Soc., Bot. 12: 433. 1869; Pilotrichella viridis (Müll. Hal.) A. Jaeger, Ber. Thätigk. St. Gallischen Natur-wiss. Ges. 1875-76: 258. 1877; Orthostichella viridis (Müll. Hal.) Müll. Hal., Linnaea 42: 493. 1879, comb, inval. Pilotrichella pulchella Schimp. ex Besch., Mém. Soc. Sci. Nat. Cherbourg 16: 222. 1872. Orthostichella filamentosula Müll. Hal., Bull. Herb. Boissier 5: 204. 1897; Pilotrichella filamentosula (Müll. Hal.) Paris, Index Bryol. Suppl. 271. 1900. Discussion. Orthostichella pentasticha is used as the name for our plants with some reservation. The type is from Réunion, and although I have not seen it, plants from East Africa and the Mascarenes are indeed similar to those in the New World. If this concept is correct, and most New World Orthostichella collections are not a complex of closely related species, then many more synonyms can be added to those listed above. The above gametophytic description is based on Antillean material and does not represent variation from throughout the range. In many ways, though, our plants look just like those from afar, with a strong tendency for caducous leaves resulting in naked branches (like in forms of Meteorium nigricans) and with a similar leaf shape and a similar areolation. Orthostichella pentasticha can be told from O. hexasticha by leaves spreading from the insertion and without an obviously differentiated leaf base. The leaf cells are thinner-walled. The vaginular hairs are included within the perichaetial leaves rather than long-exserted as in O. hexasticha.

  • Distribution

    Range. Mexico south through Central America and then through the Andes south to northern Argentina, southeastern Brazil, tropical Africa; Cuba, Puerto Rico; growing on trees and shrubs, less often on rocks, in humid forests, at 500-1900 m.

    Mexico North America| Central America| Brazil South America| Venezuela South America| Colombia South America| Ecuador South America| Peru South America| Bolivia South America| Chile South America| Argentina South America| Cuba South America| Puerto Rico South America| Africa|