Hypnum amabile (Mitt.) Hampe

  • Authority

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

  • Family

    Hypnaceae

  • Scientific Name

    Hypnum amabile (Mitt.) Hampe

  • Description

    Species Description - Plants medium-sized to somewhat robust, in often lustrous, stiff, mostly golden-green, often extensive, dense mats. Stems creeping or ascending, to ca. 12 cm long, often regularly and densely pinnate, the branches straight to slightly flexuose, to ca. 1 cm long; in cross-section without a hyalodermis, with 3-5 rows of small thick-walled colored cells surrounding larger thinner-walled cells, central strand small, of small thin-walled cells; pseudoparaphyllia foliose; axillary hairs with a single short brown basal cell and 2 elongate hyaline distal cells. Stem and branch leaves somewhat differentiated, stem leaves falcate-secund, ovate, 2.8-3.4 mm long, gradually long-acuminate, concave, strongly plicate, subcordate at base, decurrent; margins serrulate above, subentire below, mostly plane, sometimes variously recurved or incurved; costa short and double, <1/8 the leaf length, sometimes lacking; cells linear, subflexuose, 15-30:1, smooth, thick-walled, porose, becoming shorter and broader toward the insertion; alar cells well differentiated, mostly decurrent, large, thin-walled, hyaline, in several rows in extreme angles, often remaining on stem after dissection, with a small group of subquadrate cells above them. Branch leaves falcate-secund, ovate-lanceolate to oblong-ovate, 1.5-2.1 mm long, gradually long-acuminate, concave, occasionally plicate, slightly curved to the insertion, decurrent; margins serrulate above, subentire to subserrulate below, plane or variously recurved; costa short and double, occasionally longer, to 1/5 the leaf length, usually shorter; cells linear, subflexuose, 15-30:1, smooth, thick-walled, porose, becoming shorter and broader toward the insertion; alar cells decurrent, large, thin-walled, hyaline, in 2-3 rows in extreme angles, usually remaining on branches after dissection, with a few subquadrate cells above them. Asexual propagula none. Dioicous. Sporophytes unknown.

  • Discussion

    1. Hypnum amabile (Mitt.) Hampe, Bot. Zeitung (Berlin) 27: 869. 1869; Ectropothecium amabile Mitt., J. Linn. Soc., Bot. 12: 513. 1869; Stereodon amabilis (Mitt.) Broth, in Engl. & Prantl, Nat. Pflanzenfam. 1(3): 1071. 1908. Plate 118, figures 1-7 Hypnum subimponens Hampe, Ann. Sci. Nat. Bot. V, 5: 321. 1866, hom, illeg., non Lesq., Trans. Amer. Philos. Soc. II, 13: 14. 1865. Hypnum lejolisii Besch., Mém. Soc. Sci. Nat. Cherbourg 16: 252. 1872, fide Cardot, Rev. Bryol. 38: 105. 1911. Discussion. Hypnum amabile has long-acuminate leaves that are only serrulate above. The alar cells are decurrent, large, lax and hyaline. In aspect it is very similar to H. polypterum but may be told, with experience, by the somewhat larger size and the larger ratio of the length of stem leaf to branch leaf. Microscopically the less toothed leaf margins and the well-developed hyaline alar cells make separation easy.

  • Distribution

    Range. Mexico, Guatemala, Colombia and Venezuela to Bolivia, Brazil; Hispaniola (Dominican Republic); mostly growing on soil or humus, often in exposed habitats, above 1500 m.

    Mexico North America| Guatemala Central America| Colombia South America| Venezuela South America| Bolivia South America| Brazil South America| Peru South America| Ecuador South America| Colombia South America| Haiti South America| Dominican Republic South America|