Groutiella apiculata (Hook.) H.A.Crum & Steere
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Authority
Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
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Family
Orthotrichaceae
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Scientific Name
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Description
Species Description - Plants about 1-2 cm high, light-green above, olive-green to brown below, in low, spreading, dense mats. Stems creeping, tomentose below, producing numerous erect branches 3 to 7 mm, sometimes up to 2 cm high. Leaves irregularly and loosely contorted-twisted, sometimes ± spirally twisted around the branches with the laminae folded back on themselves when dry, wide-spreading and ± reflexed when moist, with laminae broadly reflexed when moist, never rugose, rarely undulate, not or scarcely plicate, 1.3-2 mm long, keeled, ligulate to oblong, obtuse to abruptly acuminate, stoutly apiculate to cuspidate; margins entire; costa excurrent and ± filling the apiculus; upper cells 7-10 µm wide, hexagonal-rounded, bulging; lower cells slightly larger, rounded to elliptic-rectangular, unipapillose at base; leaves bordered in the lower 1/3 by several rows of elongate, thick-walled cells, sometimes with 1 row of elongate, thin-walled cells at the extreme base of the leaf; basal cells near the costa not much enlarged and thin-walled. Pseudautoicous (with dwarf male plants on leaves). Setae 3-8 mm long; capsules 1-3 mm long, brown, ± dull, ovoid to oblong-ovoid, smooth to wrinkled when old and dry, gradually narrowed to the seta; exothecial cells irregularly rectangular, about 2:1; stomata not common, poorly developed, in the neck; peristome consisting of a low, papillose, unistratose membrane. Spores 12-17 µm and 20-30 µm, anisosporous, coarsely papillose. Calyptrae naked, regularly lobed at base, less than half the capsule length, with the beak half the calyptra length.
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Discussion
Fig. 482
G. apiculata (Hook.) Crum & Steere, Bryologist 53: 146. 1950.
Orthotrichum apiculatum Hook., Musci Exot. 1: pl. 45. 1818.
O. mucronifolium Hook. &Grev., Edinb. J. Sci. 1: 116. 1824.
Macromitrium mucronifolium (Hook. & Grev.) Schwaegr., Sp. Muse. Suppl. 2(2): 60. 1826.
M. macrostomum Schwaegr., Sp. Muse Suppl. 2, 2(2): 132. 1827.
M. brevipes C. Mull., Syn. Muse. Frond. 1: 728. 1849.
Micromitrium apiculatum (Hook.) Grout, Bryologist 47: 3. 1944.
M. mucronifolium (Hook. & Grev.) Grout, Bryologist 47: 3. 1944.
Craspedophyllum apiculatum (Hook.) Grout, N. Amer. Fl. 15A: 40. 1946.
C. mucronifolium (Hook. & Grev.) Grout, N. Amer. Fl. 15A: 39.1946.
Groutiella mucronifolia (Hook. & Grev.) Crum & Steere, Bryologist 53: 146. 1950.
Crosby (1970) has found that the variability in stem height, length of basal leaf borders, and leaf apex morphology is such that populations usually referred to G. apiculata and G. mucronifolia can be included in a single species, as G. mucronifolia, except for the type collection of G. apiculata (Jalapa, Mexico, Humboldt & Bonpland, NY), which he retained under the name G. apiculata. However, the types seem to m e indistinguishable. The ligulate-oblong leaves rather quickly narrow to a stout apiculus or cusp (usually longer than 40 µm), and the costa is usually excurrent and forms most ofthe cusp. The leaves are rather narrow, generally having a length/width ratio greater than 3.3:1, with only the upper margins reflexed when moist and no broad plications. The height of the branches and length of the border are variable characters and do not differentiate G. apiculata from G. tumidula. The latter has broader, ligulate leaves that are rounded to obtuse and mucronate, with the costa ending below the mucro in most leaves. Both species are rare in Mexico and restricted to eastern portions of the country, as opposed to G. tomentosa and the very common G. chimborazensis, which occupy montane forests in the interior. (Groutiella apiculata is more widespread in the West Indies than G. tumidula.)
The types of G. mucronifolia and G. brevipes show identical characteristics to that of G. apiculata, whereas G. obtusa (Mitt.) Florsch. and its synonym G. rugosa (Grout) Crum & Steere represent a separate species with small, slender, rugose leaves (found in the West Indies, Central America, and northern South America).
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Distribution
On trunks and branches oftrees; Michoacan, San Luis Potosi, Veracruz.—Mexico; Central America; northern South America and southern Brazil; West Indies.
Mexico North America| Central America| West Indies| Venezuela South America| Canada North America| Ecuador South America| Brazil South America| Guyana South America| Suriname South America| French Guiana South America| Peru South America|