Zygodon reinwardtii (Hornsch.) A.Braun

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

Orthotrichaceae

Scientific Name

Zygodon reinwardtii (Hornsch.) A.Braun

Description

Species Description - Plants up to 2 cm high, light- to yellow-green above, darker and often densely tomentose below, forming loose tufts and mats. Stems irregularly branched, in section showing large, thin-walled, central cells, those at the surface smaller and thick-walled. Brood bodies rounded-clavate, clavate, or fusiform, brown, with or without vertical walls, of various numbers of cells and sizes. Leaves irregularly twisted or curved, loosely spiraled around the stem and ± undulate when dry, spreading to wide-spreading, sometimes subsquarrose, ± recurved, and undulate when moist, (1.5-)2-2.5 mm long, keeled, narrowly oblong-lanceolate to broadly lanceolate, sharply acute and ending in a 1- to several-celled apiculus (sometimes broken off), decurrent; margins entire below, sharply and irregularly toothed in the upper 1/4, rarely almost entire or with only 1-2 teeth at the apex, often reflexed below; costa ending just below or near the apex, smooth, not covered by papillose, quadrate cells at back except at the apex; upper cells 6-12 µm wide, irregularly rounded to elliptic-hexagonal, moderately thick-walled, with 3-6, small, rounded papillae per cell; basal cells elongate and smooth near the costa, shorter and ± oblong-quadrate near the margins. Synoicous or autoicous. Setae(4-)8-13 mm long; capsules 1.5-2.5 mm long, ovate-fusiform to obovatc-oblong when mature, elliptic-oblong to narrowly cylindric when old and dry, sometimes slightly curved, strongly 8-ribbed the entire length, contracted to the seta through a well-developed neck; operculum longrostrate; exothecial cells not much differentiated into bands; stomata numerous, in the neck; peristome none or consisting of 8 fragile, rudimentary, irregularly papillose-striate endostome segments. Spores 18-25 µm coarsely papillose. Calyptrae cucullate, smooth, naked.

Discussion

Fig. 451

Z. reinwardtii (Hornsch.) Braun ex B.S.G., Bryol. Eur. 3(fasc. 4) 41. 1838.

Syrrhopodon reinwardtii Hornsch., Nova Acta Acad. Caes. Leop. Carol. German. Nat. Cur. 14(2): 700. 1829.

Zygodon denticulatus Tayl., London J. Bot. 6: 329. 1847.

Z andinusMitt, J. Linn. Soc, Bot. 12: 236. 1869.

Z. circinatus Schimp. ex Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 187. 1872.

This species presents a confusing array of variability, yet it is easily identified in relation to the other Mexican species. The irregularly twisted and curved, rather broad leaves are characteristic. The abaxial surface of the costa is smooth (except at the apex) and composed of elongate cells extending to just below the apex. Also the sexual condition is synoicous or autoicous, and the upper leaf margins are usually irregularly and coarsely serrulate. All other Mexican species have at least the upper one-fourth of the costa covered at back by papillose, quadrate cells. The var. subintegrifolius Malta is name of doubtful value applied to the more or less entire -leaved form. Such specimens totally intcrjzradc with those with strong toothing. Some specimens called the var sub integrifolius are best referred to Z. ehrenbergii (which has narrower, less curved leaves and dioicous sexuality).

Distribution

On trees of various kinds at elevations of 1000-2600 m; Chiapas, Distrito Federal, Hidalgo, Mexico, Michoacan, Oaxaca, Puebla, Veracruz.—Mexico; widespread in the Old and New Worlds, especially in the tropics (reported from Central America, northern South America, Jamaica, and the Dominican Republic; India, southeastern Asia, the Philippine Islands, Java, New Guinea, and Tasmania).