Tococa cordata O.Berg ex Triana

  • Authority

    Michelangeli, Fabián A. 2005. (Melastomataceae). Fl. Neotrop. Monogr. 98: 1-114. (Published by NYBG Press)

  • Family

    Melastomataceae

  • Scientific Name

    Tococa cordata O.Berg ex Triana

  • Type

    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

    Species Description - Shrub, to 2.5 m tall; stems with a mix of glandular and nonglandular setae, the trichomes 1.0-2.0 mm long, caducous, the nodes glabrous. 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, adaxial surface sparsely glandular- setose, abaxial surface sparsely glandular-pubescent, densely hirsute to glandular-setose on the primary and secondary veins, light green, (5-)7-plinervate, chartaceous, slightly ciliolate-serrulate; petioles 2-11 cm long, glandular; domatia immersed in the leaf blade, with base of blade attached to adaxial surface, 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 dichasium 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; outer calyx teeth highly reduced, 0.2-0.5 mm long, not projecting above the inner teeth, inner calyx teeth deltoid to ovate, 1.5-3.0 mm long, fused at the base 1.5-2.1 mm, glandular-setose; the ring inside the torus glabrous; petals 5, obovate, 13-14 X 8-9 mm, base attenuate, apex emarginate, pruinose, with an apical, caduceus, glandular seta, pink; stamens all the same size; 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, ½ 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; 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.

  • Discussion

    Tococa cordata has been rarely collected and 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, outer 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 presence of large bracts in the inflorescence is 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).

  • Distribution

    S Venezuela and N Brazil in the upper Río Negro basin, perhaps also occurring in SE Colombia, endemic on the tops of river banks of the Casiquiare and the upper Río Negro and its tributaries, from 100-120 m. Flowering May-November.

    Amazonas Venezuela South America| Amazonas Brazil South America|