Vetaforma dusenii (Steph.) Fulford & J.Taylor
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Authority
Fulford, Margaret H. 1963. Manual of the leafy Hepaticae of Latin America--Part I. Mem. New York Bot. Gard. 11: 1-172.
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Family
Vetaformaceae
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Scientific Name
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Description
Species Description - Plants of small to medium size, erect, radially symmetric or nearly so, flaccid, pale green, in tufts or among other bryophytes; stems slender, to 4 cm long, with leaves to 1.0 mm wide, irregularly branched; lateral branches frequent, of the Frullania type with the bifid half-leaf at the dorsal base, or axillary-intercalary, the intercalary branches also from the stem at the ventral base of the leaf, or at either side of the underleaf, or in the axils of male bracts and bracteoles, the subfloral innovations of the Frullania type; stem in transverse section seven to nine cells across, the cells of the unistratose cortical layer mostly smaller than those of the medulla, the walls thickened, trigones and pits present. Rhizoids very long, hyaline, from the bases of the leaves and underleaves of the lower part of the stem, and the cells surrounding the bases of the lower intercalary branches, 18-26 µ, wide, producing terminal, multicellular regenerant protonemata, which become intercalary by the development of more rhizoids with regenerant tips. Line of leaf insertion transverse. Leaves distant to imbricate, erect-spreading, cuneate, 0.8-1.0 mm long, bisbifid (some trifid with one sinus deeper, rarely bifid) to one-half of the length; segments lanceolate, erect-spreading, four (three to six) colls wide at the base, the apex short-acuminate, ending in a row of two cells; lamina as long as the segments, the margin entire; leaf-cells of the base of a segment 36-90 X 27—30 µ, the marginal cells smaller, the walls uniformly thickened, without trigones, the cuticle faintly striate. Underleaves like the leaves. Plants dioicous. Male inflorescence terminal on the stem or branch, soon becoming intercalary, the stem showing a series of shorter bracts and bracteoles separated by series of normal leaves and underleaves, the bracts and bracteoles similar, slightly smaller than the leaves, in four to ten series, mostly trifid, deeply pouched; antheridia large, spherical, pale, in the axils of both bracts and bracteoles, the wall cells hexagonal in outline, the stalk six or more cells long. Female inflorescence terminal on a stem or branch, usually with one or two innovations of the Fritllania type, the bracts and bracteoles in three series, like the leaves; archegonia six to ten, cylindric, the necks broad. Perianth absent. Sporophyte enclosed in a coelocaule; coelocaule long, club-shaped, several layers of cells thick, the surface without paraphyllia, bearing the three series of bracts and bracteoles in three rows; unfertilized archegonia at and near the tip. Vegetative reproduction through globose or cylindric masses of cells (proton-emata) produced at the tips of the rhizoids. Sporophytes not seen. Fig. 1, a-p.
Distribution and Ecology - Habitat: Sand and glacial detritus in wet places.
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Discussion
Lepidozia dusenii Stephani, Bihang, Sv. Vet.-akad Handl. III. 266: 52. 1900. Blepharostoma dusenii Stephani, Spec. Hep. 3: 640. 1909. [not “loc. cit” of the above (1900), as incorrectly cited by Stephani in later works.] Lepicolea abnormis Stephani, Sv. Vet.-akad. Handl. 469: 72. 1911. Yetaformis abnormis (Stephani), Fulford & J. Taylor, Nova Hedwigia 1: 406. f. 1-31. 1960. Temnoma dusenii (Stephani) Schuster, Bryologist 62: 240. 1959.