Tococa erythrophylla (Ule) Wurdack
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Family
Melastomataceae (Magnoliophyta)
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Scientific Name
Tococa erythrophylla (Ule) Wurdack
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Primary Citation
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Basionym
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Description
Description Author and Date: Fabian A. Michelangeli, January 2010, based on Michelangeli, F. A. (2005). Tococa (Melastomataceae). Flora Neotropica Monographs 98: 1-114.
Type: Guyana (British Guayana). Cuyuni-Mazaruni: Roraima, 2000 m, FEB 1910, Ule 8679 (holotype B [destroyed]; isotype K [not found]). Neotype, designated by Michelangeli (2001a). Guyana (British Guayana). Partang River, Merume Mountains, upper Mazaruni river Basin, 3 JUL 1960, Tillett, Tillett & Boyan 43984, (neotype, US; isoneotypes, K, P, US).
Description: Shrub or small tree, to 0.5-6.0 m tall. Stems glabrous, the nodes glabrous. Petioles 1-4 cm long, glabrous. Leaves isophyllous, elliptic-oblong, 5-15 x 2.5-8.0 cm, apex acute to obtuse, occasionally round, base broadly acute to round, adaxial surface glabrous to sparsely glandular setose, abaxial surface glabrous to sparsely glandular setose, red to crimson, with (1-) 2-3 pairs of secondary veins, nervate to plinervate, the first pair of secondary veins diverging up to 2 cm from the base of the leaf, coriaceous, ciliate-serrulate; domatia absent. Inflorescence a terminal panicle, of 6-18 flowers, 5-12 cm long, the axis green, flattened. Flowers on pedicels 0-5 mm long, articulated at the base of the hypanthium, flared at the apex, subtended by late caducous to persistent bracts, lanceolate, 0.5 mm long; hypanthium campanulate, 3.5-4.5 mm long, glabrous; calyx tube obscurely 5-lobed, 1.3-1.5 mm long, calyx teeth highly reduced, often inconspicuous; the ring inside the torus glabrous. Petals 5, oblong-obovate, 5.5-6.5 x 4.0-4.5 mm, emarginated, pruinosus, glabrous, white to pink. Stamens all of the same size, the filaments 5.0-6.5 mm long, glabrous; anthers yellow; the connective with or without a dorsal-basal blunt tooth; thecae 5.5-6.0 mm long, opening by a ventrally inclined pore. Ovary 3-locular, 1/2 inferior, the superior portion terete, the apex with a glabrous ring, 0.5-0.7 mm tall, rarely with sparse minute sessile glands; style glabrous, 11-12 mm long; stigma peltate to capitate, 1.0 mm wide. Fruits globose, 6-9.5 mm long, black, glabrous. The seeds not evident through the pericarp, truncate-obovate, 0.8-1.0 mm long, without capitate trichomes in the raphal area, without sculpturing, anticlinal walls straight, periclinal walls flat. Chromosome number n= unknown.
Habitat and Distribution: Growing in forests and scrubs in SE Venezuela and S Guyana from 1000 to 2200 m in the summits and slopes of the Guayana Highlands.
Taxonomy and Systematics: Tococa erythrophylla is resolved in the morphological phylogenetic analysis as the most basal species of the Tococa sensu stricto clade, and it can be easily recognized by its leaves with a glabrous and red abaxial surface. The presence of seeds with testa cells with straight anticlinal walls is the most important character that distinguishes T. erythrophylla from the species outside Tococa sensu stricto. Tococa erythrophylla is the only species, besides T. macrosperma, that is polymorphic for the presence of the blunt tooth at the dorsal base of the anther connective. Steyermark 109402, from Cerro Jaua, seems to be a mixed collection of T. erythrophylla and T. obovata subsp. obovata. However, the material that closely resembles T. erythrophylla is in fruit and not in flower, therefore this determination is temporary, until more material from this locality becomes available.
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Floras and Monographs
Tococa erythrophylla (Ule) Wurdack: [Article] Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Tococa erythrophylla (Ule) Wurdack: [Article] Michelangeli, Fabián A. 2005.
(Melastomataceae). Fl. Neotrop. Monogr. 98: 1-114.