Micropterygium tumidulum Fulford
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Authority
Fulford, Margaret H. 1966. Manual of the leafy Hepaticae of Latin America--Part II. Mem. New York Bot. Gard. 11: 173-276.
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Family
Lepidoziaceae
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Scientific Name
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Description
Latin Diagnosis - Caules foliosi parvi, graciles, compacti, 0.5-1 cm longi; folia symmetrica, concava, inflata, patenti-ascendentia, apice sursum curvato, marginibus integris, ala parva nonnunquam praesenti in parte superiore; cellulae 15 × 15 µ, parietibus incrassatis, trigonibus magnis lateribus convexis, luminibus angulari-rotundis, cuticulo aspero-verruculoso verrucis magnis rotundis.
Species Description - Leafy stems small, compact, slender, greenish to yellow-brown, prostrate to ascendent from a branched rhizome system; stems 0.5-1 cm long, with leaves to 0.5 mm broad, often abundantly branched, the branches at first radial with small, orbicular leaves and underleaves, becoming larger, dorsiventral with obscure underleaves in the upper two-thirds, or occasionally fiagelliform. Rhizoids on the scale-leaves of the rhizome and the flagelliform branches. Leaves densely imbricate, symmetric, concave, strongly inflated, spreading, becoming ascendent in the outer part, the apex curved upward, often bifid by a pair of cells, a short, narrow wing sometimes present, the margins entire; cells quadrate in outline, mostly 15 × 15 µ, the walls thickened, trigones large with bulging sides, the lumina angular-rounded, the cell surface covered with rounded to elongate warts as in the genus Mijtilopsis. Underleaves of the base of the shoot rounded, as broad as the stem, becoming progressively smaller upward, reduced to only a few cells near the stem tip. Female branches frequent, short, several on the lower part of a stem or the rhizome, the bracts and bracteoles ovate to ovate-lanceolate, the lateral margins of the inner series serrate and dentate, the apical part of several long laciniae. Male branches, perianth and sporophytes not seen. Pl. (34. Fig. 18, a-d.
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Discussion
This species shows a combination of the characters of several other members of the genus. The tendency toward a decrease in size of the underleaves from the base to the tip of the leafy stem is characteristic of several species. The size and general hal)it of the plant suggests M. exalatum of Puerto Rico and Dominica but differs particularly in the very large warts of the cuticle. In M . exalatum the cuticle has very small, scarcely noticable verruculae. The cells and warty cuticle are like those of plants of the monotypic Mytilopsis albifrons. Furthermore, in the latter, on the srrialler-leaved lower part of a leafy branch (a reversion), the leaves are inflated, and large, orbicular underleaves are present. In the adnlt stems of Mytilopsis in contrast, the leaves are flat, complicate, equitant, and deeply bifid. Underleaves are absent.
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Distribution
Habitat: In moist base of sandstone escarpment.
Venezuela South America|