Taxiphyllum taxirameum (Mitt.) M.Fleisch.

Authority

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

Family

Hypnaceae

Scientific Name

Taxiphyllum taxirameum (Mitt.) M.Fleisch.

Description

Species Description - Plants medium-sized to relatively robust, in lustrous, soft, yellow- to dark-green, often extensive, loose, flat mats. Stems creeping, to 6 cm long, sparsely and irregularly branched, sometimes simple, the branches prostrate, complanate-foliate; in crosssection with 2-3 rows of small thick-walled cells surrounding larger thinner-walled cells, central strand small, of small thin-walled nodulose cells; pseudoparaphyllia foliose; axillary hairs with 1-2 short brown basal cells and a single elongate hyaline distal cell. Stem and branch leaves similar, the stem leaves sometimes somewhat larger, usually distantly inserted, rarely imbricate, complanate, wide-spreading to squarrose, ± symmetric, ovate-lanceolate, (1-) 1.4-2(-2.5) mm long, smaller in colonizing forms, gradually broadly acuminate, often somewhat concave, rarely subplicate, not decurrent; margins finely serrulate throughout, mostly plane, occasionally erect or recurved; costa short and double, unequal, with one fork sometimes to 1/4 the leaf length, sometimes absent; cells linear-flexuose, mostly smooth, sometimes prorulose at upper ends at back, thin- to firm-walled, not or scarcely porose, shorter in the apex, becoming rectangular in 1-2 rows across the insertion; alar cells in extreme angles, extending up the margins by 3-7 cells, quadrate to short-rectangular. Asexual propagula not seen. Dioicous. [Sporophytes not seen from the West Indies; description based on a specimen from Kentucky.] Perichaetial leaves erect, lanceolate to lanceolate-ovate, 1.1-1.4 mm long, acuminate, often constricted at base of acumen, concave; margins serrulate throughout, often recurved above, sometimes plane throughout; costa short and double or often none; cells linear-flexuose, mostly smooth, firm-walled, becoming laxly rectangular toward the insertion; alar cells not differentiated. Setae elongate, smooth, reddish, 0.7-1.5 cm long; capsules horizontal to pendent, ± arcuate, asymmetric, short-cylindric, 1-1.5 mm long, constricted below the mouth when dry; exothecial cells ± isodiametric, thin-walled, obscurely collenchymatous; annulus of 2 rows of small subquadrate thin-walled cells, tardily deciduous; operculum obliquely conic-rostrate; exostome teeth shouldered, bordered, on the front surface cross-striolate below, coarsely papillose above, trabeculate at back; endostome with a high, smooth basal membrane, segments papillose, keeled, not or rarely narrowly perforate, ca. as long as the teeth, cilia papillose, in groups of 2-4. Spores spherical, finely papillose, 11-13 µm diam. Calyptrae cucullate, naked, smooth.

Discussion

1. Taxiphyllum taxirameum (Mitt.) M. Fleisch., Musci Buitenzorg 4: 1435. 1923; Stereodon taxirameus Mitt., J. Proc. Linn. Soc., Bot. Suppl. 1: 105. 1859; Isopterygium taxirameum (Mitt.) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1876-77: 439. 1878. Plate 128, figures 1-6 Isopterygium planissimum Mitt., J. Linn. Soc., Bot. 12: 498. 1869; Taxiphyllum planissimum (Mitt.) Broth. in Engl., Nat. Pflanzenfam., ed. 2, 11: 463. 1925; Plagiothecium planissimum (Mitt.) E. B. Bartram, Bryologist 49: 122. 1946. Isopterygium elegantifrons Müll. Hal., Hedwigia 37: 251. 1898; Taxicaulis elegantifrons (Müll. Hal.) Paris, Index Bryol. Suppl. 218. 1900; Taxiphyllum elegantifrons (Müll. Hal.) Broth, in Engl., Nat. Pflanzenfam., ed. 2, 11: 463. 1925. Discussion. Taxiphyllum taxirameum is our most common and largest member of the genus. The distantly placed, complanate leaves that are gradually broadly acuminate aid in recognition. At times it is uncomfortably close to T. deplanatum (Sull.) M. Fleisch. of eastern North America, which fortunately does not occur in the West Indies. An examination of the type of T. taxirameum from the Himalayan Mountains indicates that it is truly inseparable from North American material. However, tropical American material, long known as T. planissimum, is usually more robust with longer acuminate leaves. A more thorough investigation of the species throughout its entire range will be necessary before reinstatement of T. planissimum is justified.

Distribution

Range. Eastern North America from New York and Iowa south to Florida and eastern Texas, Arizona and New Mexico, Mexico, Central America, northern South America, eastern Asia from Japan to Malaysia, Himalaya, Sri Lanka; Bermuda, Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico, Nevis; relatively common on shaded, usually calcareous rock and soil, rarely on bases of trees and logs, in mesic forests, usually at 100-1500 m.

United States of America North America| Mexico North America| Central America| Venezuela South America| Colombia South America| Guyana South America| Suriname South America| French Guiana South America| Brazil South America| Japan Asia| China Asia| Philippines Asia| Malaysia Asia| Pakistan Asia| Nepal Asia| Bhutan Asia| India Asia| China Asia| Sri Lanka Bermuda South America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Puerto Rico South America|