Monographs Details: Hypnum amabile (Mitt.) Hampe
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
Family:Hypnaceae
Description:Species Description - Plants robust, yellow-green to yellow-brown. Stems prostrate, up to 10 cm or more long, regularly loose- to dense-pinnate; branches patent, rarely ascending and curved, up to 1.5 cm long. Stem leaves falcate-secund, broadly ovate-lanceolate, 3-3.5(-4) x 0.9-1.5 mm, gradually narrowed to a comparatively short to long, slender, sometimes circinate acumen, subcordate and decurrent at base, ± plicate; margins subentire to serrulate above, plane; costa short or rather long, u p to 1/3 the leaf length; upper median cells (50-)60-80(-90) x 3-5 µm; basal cells sometimes yellow- to red-brown; alar cells numerous, enlarged-rectangular, and thin-walled in well-defined, hyaline regions edged above by smaller, subquadrate to rectangular cells. Branch leaves smaller, oblong-lanceolate, 1.5-2 x 0.5-0.7 mm; margins sometimes recurved below; alar cells much less differentiated, with 1 or a few enlarged hyaline ceUs at extreme angles. Sporophytes unknown.

Discussion:

Fig. 774

H. amabile (Mitt.) Hampe, Bot. Zeitung 27: 869. 1869.

H. subimponens Hampe, Ann. Sci. Nat. Bot. V, 5: 321. 1866, non Lesq., 1865.

Ectropothecium amabile Mitt., J. Linn. Soc, Bot. 12: 513. 1869.

Hypnum le-jolisii Besch., Mem. Soc. Sci. Nat Cherbourg. 16: 252. 1872.

H. formosum Besch. in Fourn., Mex. Pl. 1: 54. 1872.

Cupressina producta C. Mull., Bull. Herb. Boissier 6: 122. 1898.

Hypnum productum (C. Mull.) Broth, in E. & P., Nat. Pfl. ed. 2, 11: 454. 1925.

Hypnum amabile is separated from other Mexican species by stem leaves with well-defined, decurrent alar regions consisting of enlarged hyaline cells. It is most closely related to H . macrogynum Besch. of eastern Asia but differs in a somewhat larger size (in H . macrogynum, stem leaves 1.6-2.7 x 0.7-1.2 mm), longer leaf cells (50-70, rarely 80 µm long in H. macrogynum), and more remarkably decurrent alar groups in stem leaves. It is distinguished from H. curvifolium Hedw. of eastern North America as follows: plants larger and usually less complanate-foliate; leaves less cordate at base; margins of branch leaves sometimes recurved below (always plane in H. curvifolium); leaf cells longer (50-70 µm in H . curvifolium); and alar groups of stem leaves decurrent and better differentiated, with enlarged-rectangular, hyaline cells.

Distribution:Brazil South America| Bolivia South America| Ecuador South America| Venezuela South America| Colombia South America| Dominican Republic South America| Central America| Mexico North America|