Tococa hirta O.Berg ex Triana

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Tococa hirta O.Berg ex Triana

  • Primary Citation

    Trans. Linn. Soc. London 28(1): 132. 1871

  • 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: Venezuela. Amazonas: San Carlos de Río Negro, Spruce 3145 (lectotype, K, designated by Michelangeli (2001a); isolectotypes BR, P).

    Description: Shrub, to 0.5-2.0 (-3.0) m tall. Stems densely glandular setose, the trichomes 1.5-2.5 mm long, persistent, the nodes glabrous. Petioles 0.5-1.0 (-1.5) cm long, glandular setose. Leaves isophyllous, ovate to oblong, 8-16 x 4-8 cm, apex acute, base cordate, the sinus up to 1 cm wide, adaxial surface adpressed-setose, abaxial surface sparsely glandular setose, hirsute on the primary and secondary nerves, light green, with 2 pairs of secondary veins, basally nervate, membranaceous, ciliolate; domatia 1/4 to 1/3 immersed in the leaf blade, globose to ovoid, 0.8-1.2 x 0.7-1.1 cm. Inflorescence a pseudo-axillary panicle, rarely terminal, of 3-9 flowers, 5-12 cm long, the axis dark red to magenta, flattened, sparsely glandular setose, branched above a peduncle 2-3 cm long, subtended by a caducous, sheathing, bract, 2.5 cm long. Flowers on pedicels 6-10 mm long, not flared at the apex, articulated at the base of the hypanthium; hypanthium conical, 3.5-5.0 mm long, glabrous; sepals deltoid to ovate, fused at the base 1/2 of the length, 2.5 mm long, the inner surface covered by minute sessile glands, calyx teeth reduced and inconspicuous, sometimes with a short apical glandular seta or a sessile gland, 0.2 mm long; the ring inside the torus glabrous. Petals 5, oblong, 10.5-12.0 (-13.5) x 4.0-5.5 mm, base oblong to slightly attenuate, apex round and slightly emarginated, smooth, glabrous, white. Stamens all of the same size, the filaments 5.0-5.5 mm long, glabrous; anthers yellow; the connective with a dorsal-basal blunt tooth; thecae 2.7-3.2 mm long, opening by a ventrally inclined pore. Ovary 3-locular, 1/3 inferior, the superior portion broadly conical, the apex truncate; style glabrous, 12-14 mm long; stigma funneliform to capitate, papillate. Fruits globose, with the calyx persistent and slightly reflexed, 4.5-6 mm long, black, glabrous. The seeds not evident through the pericarp, truncate-obovate, 0.7-1.3 mm long, without capitate trichomes in the raphal area, without sculpturing, anticlinal walls straight, periclinal walls straight, boundaries between periclinal walls flat. Chromosome number n= unknown.

    Habitat and Distribution: Endemic to the upper Río Negro Basin in SE Colombia and S Venezuela. Often inhabiting savannas and scrub vegetation from 75 to 150 m.

    Taxonomy and Systematics: Tococa hirta is a rarely collected species, distinguishable by the sheathing bracts of the inflorescence peduncle, white petals and small, round and pubescent domatia. There is great variation in the size of the flowers and fruits of T. hirta, not seen in other species of the genus. This species is related, based on the cladistic analysis presented here, to the T. gonoptera group, based on the presence of pseudo-axillary inflorescences. However, floral morphology closely resembles that of T. guianensis and T. bullifera.

  • Floras and Monographs

    Tococa hirta O.Berg ex Triana: [Article] Michelangeli, Fabián A. 2005. (Melastomataceae). Fl. Neotrop. Monogr. 98: 1-114.