Tococa cordata O.Berg ex Triana

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Tococa cordata O.Berg ex Triana

  • Primary Citation

    Trans. Linn. Soc. London 28(1): 133. 1871

  • Type Specimens

    Specimen 1: Isolectotype -- R. Spruce 3477(2414)

  • 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: Prope San Carlos ad Río Negro in Venezuela australi, Spruce 3477 (lectotype, K designated by Michelangeli (2001a); isolectotypes, BR, K, NY, P).

    Description: Shrub, to 2.5 m tall. Stems with a mix of glandular and non-glandular setae, the trichomes 1.0-2.0 mm long, caducous, the nodes glabrous. Petioles 2-11 cm long, glandular. Leaves isophyllous, oblong to oblong-ovate, 10-25 x 5-13 cm, apex acuminate to abruptly acuminate, base cordate, the sinus up to 10 mm long, the base of the leaf blade attached to the adaxial surface of the domatium, adaxial surface sparsely glandular setose, abaxial surface sparsely glandular pubescent, densely hirsute to glandular setose on the primary and secondary veins, light green, with (2-)3 pairs of secondary veins, plinervate, chartaceous, slightly ciliolate-serrulate; domatia immersed in the leaf blade, ovoid, 1.5-2.0 (-3.0) x 1.0-1.7 cm, 4-lobulate on the abaxial side. Inflorescence a terminal panicle, of 6-15 (-20) flowers, 8-12 cm long, the axis green, flattened, sparsely glandular setose, each dicasium subtended by early caducous suborbicular bracts, up to 3 cm long. Flowers on pedicels 2-6 mm long, flared at the apex, subtended by caducous bracts, elliptic to obovate, 20-30 x 15-30 mm, the margins ciliate; hypanthium broadly conical to globose, 6 mm long, sparsely or densely glandular setose; sepals deltoid to ovate, 1.5-3.0 mm long, fused at the base 1.5-2.1 mm, glandular setose, calyx teeth highly reduced, 0.2-0.5 mm long, not projecting above the sepals; the ring inside the torus glabrous. Petals 5, obovate, 13-14 x 8-9 mm, base attenuate, apex emarginate, pruinosus, with an apical caducous glandular seta, pink. Stamens all of the same size, the filaments 7.5-8.0 mm long, glabrous; anthers blue; the connective with a dorsal-basal blunt tooth; thecae 7 mm long, opening by a dorsally inclined pore. Ovary 3-locular, 1/2 inferior, the superior portion conical, the apex with a glandular-pubescent collar; style glabrous, 15-17 mm long; stigma capitate, 1.5 mm wide. Fruits urceolate, 18-23 mm long, blue, densely glandular pubescent. The seeds not evident through the pericarp, narrowly ovate, 2.2-2.8 mm long, with capitate trichomes in the raphal area, without sculpturing, anticlinal walls straight, periclinal walls flat, boundaries between periclinal walls flat. Chromosome number n= unknown.

    Habitat and Distribution: Endemic to the upper Río Negro basin in S Venezuela and N Brazil, perhaps also occurring in SE Colombia. Growing on the top of river banks of the Casiquiare and the upper Río Negro and its tributaries, from 100 to 120 m.

    Phenology: Flowering May through November.

    Taxonomy and Systematics: Tococa cordata has been rarely collected, and it occupies environments similar to those of its close allies T. coronata and T. lancifolia. It can be distinguished from T. lancifolia by the leaf shape, and from T. coronata by the absence of vertically projecting subulate calyx teeth and the presence of 4-lobulate domatia. Tococa cordata shares with T. capitata the presence of membranaceous calyces, a unique character within the group of species with domatia immersed in the leaf blade. The large bracts in the inflorescence are a unique feature of T. cordata that sets it apart from all other species in the genus. These bracts are early caducous, thus lacking in some of the specimens observed. The lectotype was chosen so inflorescences with and without bracts are represented, following the original description by Berg (Triana 1871).

  • Floras and Monographs

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