Sematophyllum adnatum (Michx.) E.Britton

  • Authority

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

  • Family

    Sematophyllaceae

  • Scientific Name

    Sematophyllum adnatum (Michx.) E.Britton

  • Description

    Species Description - Plants smallish, in ± lustrous, pale- to golden-green, often flat, small, lax mats. Stems creeping, to ca. 3 cm long, freely but irregularly branched, the branches often ascending, short, somewhat curved; in cross-section with 1-2 rows of small thick-walled cells surrounding large thin- to firm-walled cells, central strand absent; pseudoparaphyllia foliose; axillary hairs with a single rectangular brown basal cell and 2 elongate hyaline distal cells. Stem and branch leaves similar, erect to erect-spreading, sometimes homomallous, lanceolate to oblong-lanceolate, 0.85-1.6 mm long, gradually acuminate, flat to shallowly concave; margins entire, often reflexed; costa short and double or absent; cells long-rhomboidal to linear-flexuose, 6-12:1, smooth, firm-walled, not porose, not shorter in the acumen; alar cells enlarged, ± inflated, concolorous or colored across the insertion, oblong, usually not more than 2-3 X as large as the quadrate cells above them. Asexual propagula rare in leaf axils, uniseriate, simple or little-branched, 4-12-celled, roughened (see Galloway et al., 1996). Autoicous. Perichaetial leaves erect, lanceolate to triangular, 0.5-0.9 mm long, gradually acuminate; margins subentire, plane; costa mostly none; cells long-rhomboidal to linear-flexuose, smooth, thick-walled, ± porose, becoming rectangular to subquadrate toward the insertion; alar cells not differentiated. Setae relatively short, smooth, reddish, 0.4-0.9 cm long, straight; capsules suberect, ± symmetric, short-cylindric, ca. 1 mm long, slightly constricted below the mouth when dry; exothecial cells subquadrate, strongly collenchymatous, becoming smaller, oblate and evenly firm-walled in 2-4 rows at the mouth; annulus not differentiated or with a single row of cells tardily fragmenting and usually falling with the operculum; operculum obliquely long-rostrate, shorter than the urn; exostome teeth triangular, strongly shouldered, strongly bordered, on the front surface with a zig-zag median line, cross-striolate below, coarsely papillose above, trabeculate at back; endostome with a fairly high basal membrane, segments smooth to finely papillose, keeled, narrowly perforate, almost as long as the teeth, cilia none or rudimentary. Spores spherical, finely papillose, 10-17 µm diam. Calyptrae cucullate, naked, smooth.

  • Discussion

    3. Sematophyllum adnatum (Michx.) E. Britton, Bryologist 5: 65. 1902; Leskea adnata Michx., Fl. Bor.-Amer. 2: 310. 1803; Rhaphidostegium adnatum (Michx.) Gier, Trans. Kansas Acad. Sci. 58: 46. 1955, nom. inval. in syn. Plate 148, figures 9-18 Leskea microcarpa R. Hedw. ex Brid., Muscol. Recent. Suppl. 2: 73. 1812 (fide Schwägr., Sp. Musc. Frond. Suppl. 1(2): 167. 1816), non Schimp. ex Sull. in A. Gray, Manual, ed. 2, 659. 1856, hom, illeg. [= Leskea australis Sharp]; Hypnum microcarpum (Brid.) Müll. Hal., Syn. Musc. Frond. 2: 326. 1851, hom, illeg., non Hedw., Sp. Musc. Frond. 244. 1801, “microcarpon” [= Distichophyllum microcarpon (Hedw.) Mitt.], nec Hook., Icon. Pl. 1: 23. 1837 [1836], hom, illeg. [= Trichosteleum brachypelma (Müll. Hal.) Paris], nec Hornsch. in Mart., Fl. Bras. 1(2): 84. 1840, hom, illeg. [= Trichosteleum subdemissum (Besch.) A. Jaeger]; Rhaphidostegium microcarpum (Brid.) A. Jaeger, Ber. Thätigk. St. Gallischen Natur-wiss. Ges. 1876-77: 396. 1878; Aptychus microcarpus (Brid.) Müll. Hal., Flora 82: 471. 1896; Sematophyllum microcarpum (Brid.) A. Jaeger ex Broth, in Engl., Nat. Pflanzenfam., ed. 2, 11: 431. 1925, hom, illeg., non Mitt., J. Linn. Soc., Bot. 12: 493. 1869 [= Trichosteleum vincentinum (Mitt.) A. Jaeger]. Hypnum admistum Sulk, Proc. Amer. Acad. Arts 5: 289. 1861; Hypnum microcarpum (Brid.) Miill. Hal. var. anisocarpum Sulk, Icon. Musc. 175. 1864; Sematophyllum admistum (Sulk) Mitt., J. Linn. Soc., Bot. 12: 485. 1869; Rhaphidostegium microcarpum var. anisocarpum (Sulk) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1876-77: 397. 1878; Rhaphidostegium microcarpum subsp. admistum (Sulk) Kindb., Canad. Rec. Sci. 6: 74. 1894, “admixtum”; Rhaphidostegium admistum (Sulk) Broth, in Engl. & Prantl, Nat. Pflanzenfam. 1(3): 1112. 1908, “admixtum"; Rhaphidostegium carolinianum var. admistum (Sulk) Grout, Moss. Hand-lens Microsc. 5: 363. 1910, “admixtum," comb. illeg. Sematophyllum constrictum Mitt., J. Linn. Soc., Bot. 12: 480. 1869; Rhaphidostegium constrictum (Sulk) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1876-77: 391. 1878. Discussion. Since this name has not been widely used in the West Indies, it deserves some explanation. Sematophyllum admistum, described from Cuba, was used for this concept until 1920 when Dixon synonymized it with S. subpinnatum (as Rhaphidostegium caespitosum). Since then material of S. adnatum in the West Indies was named S. subpinnatum, whereas specimens from North America continued to be segregated. The two species are never likely to be confused if a microscope is used, although an occasional odd specimen of one may be confused for the other with use of a hand-lens only. The leaves of S. adnatum are lanceolate and gradually acuminate. The apical leaf cells are scarcely differentiated from those below. In both species the alar cells are only enlarged but not strongly inflated, but in S. subpinnatum the differentiated cells may extend across much of the insertion whereas in S. adnatum they are always confined to the extreme angles. Sematophyllum adnatum might be confused, when sterile, with Donnellia commutata, and indeed they are almost identical gametophytically. However, both species are usually fertile and can easily be separated by sporophytic features. In S. adnatum the setae are longer, the capsule is not lageniform, and the exostome teeth are yellow and cross-striolate on the front surface. An examination of the type of S. demissum (Wilson) Mitt., the type species of the genus, described from Ireland, shows that it is very similar to and perhaps identical to S. adnatum. Material so named from eastern North America is probably not the same as European material and could be called S. carolinianum (Müll. Hal.) E. Britton. A particularly curious specimen presently referred to S. adnatum has been collected in St. Thomas, U.S. Virgin Islands (Buck 3375, NY). It differs from typical material in its smaller size, leaves with alar cells much larger than normal, setae only about 2 mm long, and spores somewhat smaller. The material is sufficient but not ample, and may represent a new species, but I am reluctant to describe it as new from a locality notably lacking in endemics.

  • Distribution

    Range. Eastern United States, from New York and Ohio south to Florida and Texas, Mexico, Central America, northern South America, tropical Africa; Bermuda, Bahamas (Abaco, Andros, Grand Bahama, New Providence, San Salvador, Watling’s Island), Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico, Virgin Islands (St. John, St. Thomas, Tortola, Virgin Gorda), St. Martin, St. Eustatius, Guadeloupe, Dominica, St. Lucia, and probably most other islands as well; growing on tree trunk

    United States of America North America| Mexico North America| Central America| Brazil South America| Peru South America| Ecuador South America| Colombia South America| Venezuela South America| Guyana South America| Suriname South America| French Guiana South America| Africa| Bermuda South America| Bahamas South America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Puerto Rico South America| Virgin Islands South America| Saint Martin South America| Sint Eustatius South America| Guadeloupe South America| Dominica South America| Saint Lucia South America|