Tococa macrophysca Spruce ex Triana

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Tococa macrophysca Spruce ex Triana

  • Primary Citation

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

  • Common Names

    Boyuyo hormiga, Boyuyo blanco

  • 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: Colombia. Vaupés: near Panure at Río Uaupes and Sao Gabriel of Rio Negro, Spruce 2188 (lectotype, K, designated by Michelangeli (2001a); isolectotypes, P, BR [fragment], V [n.v.]).

    Description: Shrub or small tree, to 1.5-3.0 (-5) m tall. Stems glandular setose, the trichomes 1.5-2.5 mm long, early caducous, the nodes glabrous. Petioles 0.5-1.5 (-3.0) cm long, densely glandular setose. Leaves isophyllous, elliptic to oblong, 15-35 (-42) x 7-13 (-16) cm, apex acute to shortly acuminate, base acute to narrowly obtuse, adaxial surface adpressed-setose, abaxial surface glabrous to sparsely setose, light green, with 2 pairs of secondary veins, basally nervate, occasionally shortly plinervate, membranaceous, entire to ciliate serrulate, occasionally slightly crenulate; domatia free from the leaf blade, narrowly obovate at the base, 2.5-5.5 (7.0) x (1.0-) 1.5-2.5) cm, with a pair of ascending lobes at the apex, up to 3.5 cm long. Inflorescence a panicle, terminal but quickly becoming axillary by overgrowth of the lateral meristem, occasionally axillary, at the base of the younger leaves, of 3-10 (-18) flowers, 3-7 cm long, the axis green, terete, sparsely glandular setose, the trichomes caducous, up to 2 mm long, occasionally with furfuraceus cadoucus trichomes. Flowers on pedicels 5-20 mm long, not flared at the apex, subtended by persistent bracts, subulate to narrowly lanceolate, 3-7 x 0.3 mm; hypanthium conical, 4.0-5.5 mm long, with a mix of sparse non-glandular trichomes and lepidote hairs; sepals broadly deltoid, connate 2/3 to 4/5 of the length, 1.5 mm long, calyx teeth subulate, 2-5 mm long; the ring inside the torus glabrous. Petals 5, obovate to oblong, 7-9 x 4-5 mm, base truncate to obtuse, slightly emarginated, smooth, glabrous, white to light pink. Stamens all of the same size, the filaments 4-5 mm long, glabrous; anthers yellow; the connective with a dorsal-basal blunt tooth; thecae 5.0-6.0 mm long, opening by a ventrally inclined pore. Ovary 3-locular, 1/2 inferior, the superior portion conical, the apex with a corona of short glandular setae; style glabrous, 10-13 (-15) mm long; stigma funneliform. Fruits globose, 6-9 mm long, black, glabrous to sparsely glandular setose. The seeds not evident through the pericarp, truncate-obovate, 0.7-1.2 mm long, without capitate trichomes in the raphal area, without sculpturing, anticlinal walls straight, periclinal walls convex, boundaries between periclinal walls flat. Chromosome number n= unknown.

    Habitat and Distribution: SE Colombia, S Venezuela and NW Brazil. Restricted to the Río Negro and Orinoco basins, in the lowlands between 100 and 400 m, although occasionally found up to 1200 m, on the slopes of some tepuis. Locally abundant in periodically flooded soils, in forest gaps, the forest-savanna ecotone, and disturbed environments.

    Taxonomy and Systematics: Tococa macrophysca is easily recognized by the two horn-like appendages at the apex of the domatia. Additionally, it can be distinguished by the combination of pseudo-axillary inflorescences, white petals and subulate outer calyx. The inflorescences of T. macrophysca often appear to be axillary, but in all individuals observed in the field the development of the inflorescences is terminal, but it is quickly overtopped by the axillary meristem that produces the extension of the stem.

  • Floras and Monographs

    Tococa macrophysca Spruce ex Triana: [Article] Maguire, Bassett, et al. 1953. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 8 (2): 87-160.

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