Thuidium delicatulum (Hedw.) Schimp.
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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
Thuidiaceae
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Scientific Name
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Description
Species Description - Plants rather robust, in often large, mostly dense, green to reddish golden mats. Stems mostly ± arched, to ca. 20 cm long, 2-3-pinnate, ± frondose; in cross-section with 3-5 rows of small thick-walled dark-red cells surrounding gradually larger and somewhat thinner-walled cells, central strand small, of very small cells; paraphyllia abundant on stems and primary branches, few or none on secondary and tertiary branches, polymorphous, mostly uniseriate but branched, some foliose with uniseriate filaments, the cells rectangular, ca. 2-3:1, papillose with papillae on almost all cells and not restricted to cell ends; pseudoparaphyllia foliose; axillary hairs with a single short brown basal cell and 2 elongate hyaline distal cells. Stem and branch leaves strongly differentiated, stem leaves appressed when dry, erect-spreading when moist, triangular-ovate, 0.6-1.4 mm long, mostly ca. 1.1-1.3 mm long in our material, ± abruptly and broadly acuminate, concave, ± plicate, short-decurrent; margins papillose-serrulate throughout, recurved in the lower 1/2 of the leaf; costa single, strong, ending ca. 4/5 the leaf length, ending in but not filling the acumen, papillose, in lower 1/3 sometimes with a few short paraphyllia; cells round to rounded-rectangular, mostly 1-5:1, unipapillose with the papillae centrally located over the lumina, stout, straight or slightly curved, thick-walled, not or slightly porose; alar cells not differentiated but cells in broad band across the insertion and into the decurrencies long-rectangular, thick-walled, porose, and smooth. Secondary and tertiary branch leaves erect-spreading, lanceolate-ovate to ovate, 0.25-0.4 mm long, acute, concave, not plicate, not decurrent; margins papillose-serrulate, plane or erect below; costa single, ending 2/3-3/4 the leaf length, often forked above; cells oval to ± short-clavate, ca. 7 µm wide, stoutly curved-unipapillose, often angular, very thick-walled, ± porose, the apical cell mostly truncate and crowned with 2-4 papillae; alar cells not differentiated. Asexual propagula none. Dioicous. [Sporophytes not known in the West Indies; description based on Pennsylvanian (topotypic) material.] Perichaetial leaves mostly erect, linear-lanceolate, to ca. 5 mm long, ending in a long-loriform apex, plicate; margins serrulate above, sparsely ciliate at ca. 2/3 the leaf length, the cilia uniseriate throughout or biseriate at their bases, plane; costa single, ending in but not filling the acumen; cells long-rectangular to linear, smooth or inconspicuously unipapillose, very thick-walled, porose. Setae elongate, stout, smooth, reddish, 1.5-4.5 cm long; capsules suberect to horizontal, asymmetric and ± arcuate, cylindric, 1.8-4 mm long; exothecial cells short-rectangular, thick-walled, becoming shorter at the mouth; annulus differentiated; operculum long-rostrate, somewhat oblique, 0.75-2 mm long; exostome teeth yellow to yellow-brown, shouldered, bordered, on the front surface cross-striolate below, then finely papillose, then coarsely papillose at apex, trabeculate at back; endostome with a high, smooth basal membrane, segments finely papillose-spiculose below, more coarsely so above, keeled, narrowly perforate, cilia finely papillose-spiculose, in groups of 2-3, nodulose. Spores spherical, finely papillose, 12-18 µm diam. Calyptrae cucullate, naked, smooth.
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Discussion
2. Thuidium delicatulum (Hedw.) Bruch & Schimp. in Bruch, Schimp. & W. Gümbel, Bryol. Eur. 5(fasc. 49/ 51, Monogr. 1): 164. 1852; Hypnum delicatulum Hedw., Sp. Musc. Frond. 260. 1801; Hypnum tamariscinum var. delicatulum (Hedw.) Brid., Muscol. Recent. Suppl. 2: 140. 1812; Leskea delicatula (Hedw.) Sw. in Muhl., Cat. Pl. Amer. Sept. 99. 1813; Thuidium recognition (Hedw.) Lindb. var. delicatulum (Hedw.) Wamst., Bot. Centralbl. 5: 185. 1881. Plate 72, figures 11-18 Discussion. Thuidium delicatulum has been misunderstood in tropical America and the name has been widely applied to almost all species of the genus. The species is characterized by paraphyllia with elongate cells, stem leaves with the costa not filling the acumen, and ovate branch leaves with thick-walled, stoutly curved-unipapillose cells. The apical cell of the branch leaves is usually crowned with 2-4 papillae. In the West Indies the only other species with long-celled paraphyllia is T. tamariscinum. Like T. delicatulum, it is known only from a single old collection; it differs, though, in the smooth apical cell on branch leaves. Thuidium tomentosum is easily separated by its pluripapillose leaf cells. Both T. urceolatum and T. pseudoprotensum have short-celled paraphyllia. Thuidium delicatulum is sometimes confused with T. recognitum (Hedw.) Lindb. in the Northern Hemisphere, but we are spared that confusion in the West Indies. In the latter species the cells of the paraphyllia are papillose only at their upper ends. Although these two names have been called into question, Crum and Anderson (1981: 909, 910) have clarified the situation and left nomenclature in accord with standard usage.
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Distribution
Range. North America, reportedly extending into Mexico, Central America and northern South America (but most reports probably in error), Europe, northern Asia; Jamaica; growing on shaded soil, humus, rocks, logs, or bases of trees. The single West Indian collection, made in the 19th century, is without habitat data. Other reports for the flora area are based on misdeterminations.
North America| Central America| Venezuela South America| Colombia South America| Brazil South America| Guyana South America| Suriname South America| French Guiana South America| Europe| Russia Asia| Jamaica South America|