Tropicos | Name - !Weissia controversa Hedw.

Cent. Amer. Moss > Pottiaceae > Weissia > Weissia controversa

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!Weissia controversa Hedw.

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Project Name Data (Last Modified On 2/16/2011)

Acceptance : Accepted

Project data (Last Modified On 2/16/2011)

Discussion:

Weissia controversa is an extremely variable species often found on bare soil in disturbed, weedy places. It is a small plant with a distinct yellowish green color and leaves that are crisped and contorted when dry. Weissia jamaicensis has similarly shaped leaves, and usually the two species are not difficult to separate due the larger size, dioicous sexual condition, and frequent presence of hyaline cells that run up the basal margin in a v-shaped pattern in W. jamaicensis. Although W. controversa has been reported from nearly every region of the world it is rare in Central America. The few collections of W. controversa examined were all depauperate and sterile. They may represent stressed, undersized plants of W. jamaicensis. Although most collections of W. jamaicensis have hyaline cells running up the basal margin in a distinct v-shaped pattern, the feature is distressingly variable, with some leaves from single collections lacking it. Conversely, the leaves on some plants of W. controversa sometimes have the feature weakly developed.

The peristome teeth of W. controversa show no sign of a basal membrane or any other feature usually associated with the Pottiaceae. Instead the teeth, although reduced, appear dicranaceous.

Illustrations: Grout (1904, Pl. 23); Bartram (1949, Fig. 40 I–L); Crum and Anderson (1981, Figs. 130 & 131); Ireland (1982, Pl. 107); Reese (1984, Fig. 26 H–J); Stoneburner (1985, Figs. 13–14); Noguchi (1988, Fig. 108 A); Zander (1993, Pl. 59 1–11); Sharp et al. (1994, Fig. 160); Allen (2000a, Fig. 2). Figure 94.

Habitat: On dry or moist soil over rock on road banks or shaded banks; 330–850 m.

Distribution in Central America: GUATEMALA. Huehuetenango: Hermann 26371 (F); Jutiapa: Standley 75228a (F). HONDURAS. Comayagua: Crosby 2805 (MO); Francisco Morazán: Standley 20979 (F); Olancho: Standley 17478 (F).

World Range: Subarctic America, Western and Eastern Canada, Northwestern, North-Central, Northeastern, Southwestern, South-Central, and Southeastern U.S.A.; Mexico; Central America; Caribbean, Western, Northern, and Southern South America, Brazil; Northern, Southwestern, Middle, Southeastern, and East Europe; Siberia, Russian Far East; Middle Asia, China, Mongolia, Eastern Asia, Caucasus, Western Asia, Arabian Peninsula; Macaronesia, Northern and Southern Africa, West, East, and South Tropical Africa, Western Indian Ocean; Indian Subcontinent, Indo-China, Malesia; Australia, New Zealand; Northwestern, North-Central, Southwestern, and South-Central Pacific.

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Weissia controversa Hedw., Sp. Musc. Frond. 67. 1801.

Protologue: Germany. Lipsiae ad rivulum post collem Bienitz.

Hymenostomum mexicanum Card., Rev. Bryol. 36: 70. 1909. Protologue: Mexico. Etat de Jalisco: Etzatlan, 1908 [Pringle] (n 15270).

Plants small, dark-green to yellow-green above, brown below, in dense mats or tufts, 2.5–5 mm high. Stems red, sparsely and irregularly branched, hyalodermis weakly developed, central strand well-developed; rhizoids sparse, red, smooth to roughened. Leaves 1.3–2.3 mm long, linear-lanceolate to lanceolate, ovate to oblong, weakly clasping to erect at base, crisped and spirally contorted above when dry, erect-flexuose to erect-spreading when wet; apices acuminate, mucronate; lamina unistratose, not fragile; margins entire, strongly involute above the base to the apex; costa stoutly excurrent, broad at base (40–80 μm), ventral surface cells quadrate, guide cells and two stereid bands well-developed, ventral surface layer enlarged, papillose, green; upper cells rounded to quadrate, 6–11 μm long, thick-walled, bulging at the surface, with 4–6 bifid papillae, basal cells narrowly rectangular, thick- or thin-walled, yellow or hyaline, smooth, 20–50 x 6–10 μm, outer basal cells hyaline, thin-walled, not or somewhat running up the margins in a v-shaped pattern. Autoicous. Perichaetial leaves somewhat larger and longer than vegetative leaves, otherwise not strongly differentiated. Sporophytes not known from Central America. Setae smooth, 4–8 mm long, yellow. Capsules ovoid to oblong, erect, 0.8–1.2 mm long, somewhat furrowed when dry; stomata in neck; opercula rostrate, 0.7–1.0 mm long; annuli of several rows of cells persistent cells; peristome teeth 16, short, narrowly triangular, erect, red, papillose, basal membrane absent, rudimentary or absent. Spores 18–22 μm, papillose. Calyptrae yellow, cucullate, smooth, 1.2 mm long.