Tococa guianensis Aubl.

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Tococa guianensis Aubl.

  • Primary Citation

    Hist. Pl. Guiane 1: 438, t. 174. 1775

  • Type Specimens

    Specimen 1: Paratype -- Y. E. J. Mexia 6363

  • Common Names

    pabojoni, e-mo-naweE, ma-eE-pa-he, pucacuru-caspi, anayo-caspi, Boyuyo, Boyuyo homiga, Buyo-Buyo

  • 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: French Guiana: Ad margines viarum Caiennae & Guianae, Aublet s. n. (holotype BM; isotypes P[2]).

    Description: Shrub or small tree, to 1-5 (-7) m tall. Stem pubescence highly variable, glabrous, sparsely glandular pubescent, or with a mix of glandular and non-glandular setae, often with a reddish or fuchsia tinge in the younger branches, the setae 2.5 mm long, occasionally up to 12 mm long, persistent, the nodes glabrous. Petioles 0.5-2.0 (-4.5) cm long, sparsely or densely glandular setose. Leaves anisophyllous, seldom isophyllous, ovate to oblong elliptic, the large leaves (5.5-) 8-30 (-34) x (4.0-) 5-15 (-18) cm, the smaller leaves 3.5-10 x 2.5-7 cm, apex acute to acuminate, caudate or aristate, base rounded to acute, occasionally attenuated, adaxial surface adpressed non-glandular setose, occasionally glandular setose, rarely glabrous, abaxial surface glandular setose, occasionally non-glandular setose, rarely glabrous, the setae denser in the primary and secondary veins, usually light green, purple or dark red in some young individuals, with 2(-3) pairs of secondary veins, basally nervate, the veins reticulate underneath, membranaceous to chartaceous, (slightly coriaceous in individuals growing in the sun), entire to ciliate-serrulate, occasionally ciliate-crenulate; domatia free from the leaf blade, globose, ovoid or narrowly ellipsoid, (1.5-) 2.0-3.0 (-4.5) x (0.7-) 1.0-2.0 (3.0) cm, sometimes present only in the larger leaf, occasionally with a purple or light red coloration. Inflorescence a terminal panicle of 8-30 (50) flowers, (3.5-) 5-15 (-21) cm long, the axis compressed, dark red to magenta, occasionally green, or turning green after it matures. Flowers on pedicels 3-9 mm long, sometimes articulate 1-2 mm below the hypanthium, flared at the apex, subtended by caducous or persistent bracts, subulate to lanceolate, 0.5-1.5 (-3.0) x 0.2-0.7 mm; hypanthium broadly conical to globose, (3.5-) 5.0-7.5 (-9.5) mm long, glabrous to densely glandular setose, or with a mix of lepidote hairs and long glandular setae up to 3.5 mm long; sepals broadly deltoid to ovate, fused halfway to the apex (0.5-1.2 mm), 1.0-3.0 mm long, calyx teeth reduced to well developed into a deltoid teeth 0.3-2.0 mm long, projecting 0 to 1.0 mm above the sepals, terminated in one or more glandular setae up to 3.5 mm long, occasionally glabrous; the ring inside the torus glabrous. Petals 5, broadly oblong to ovate, (5.5-) 6.5-15 x (3.0-) 4.5-7.5 (-9.0) mm, base attenuate, apex emarginate to obtuse, border entire, often undulate, pruinosus to smooth, sometimes finely granulose, glabrous, occasionally with a caducous terminal glandular seta, pink. Stamens all of the same size, the filaments (5.0-) 5.5-7.5 (-8.5) mm long, glabrous; anthers yellow; the connective with a dorsal-basal blunt tooth; thecae (4.5-) 5.0-7.5 (8.5) mm long, opening by a ventrally inclined pore. Ovary 3-locular, 1/2 to totally inferior, the superior portion globose to broadly conical, terminated on a ring elevated 0.1-0.5 mm over the apex of the ovary, the ring glabrous to densely pilose or with a corona of long glandular setae; style glabrous, very rarely minutely stellate pubescent at the base, 13-20 (23) mm long; stigma capitate, 1.5 mm wide (appearing funneliform when dry), the stigmatic surface finely papillate. Fruits globose, 10-19 (-22) mm long, black, glandular setulose, rarely glabrous. The seeds not evident through the pericarp, triangular, 0.6-1.2 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= 17.

    Habitat and Distribution: Widely distributed from S Mexico to N Bolivia, to the E into E Brazil and French Guiana. Growing in forested and disturbed areas, or in forested savannas from 0 to 1600 m.

    Phenology: Flowering year round, but peaking during the rainy season.

    Ecology: Tococa guianensis seems to be often associated with Azteca ants, and more rarely with Crematogaster. Even though T. guianensis is found at elevations over 1600 m, often the specimens collected over 1000 m lack any inhabiting ants. A notable exception seems to be open habitats of the Gran Sabana in SE Bolívar State in Venezuela, in which ants can be found in plants growing above 1400 m. In southern Ecuador and northern Peru the domatia can be inhabited by ants of the genus Myrmelachista. The workers of this genus create large clearings in the forest understory, which become monospecific stands of T. guianensis (Morawetz et al., 1992; Renner & Ricklefs, 1998).

    Taxonomy and Systematics: Tococa guianensis is a highly variable species widely distributed throughout the entire geographical range of the genus. It is very common in both primary and disturbed environments in the Amazon and Orinoco basins, and less frequent in northern South America and Central America. Due to the variation exhibited across the geographical range, several species have been described, most of them based on stem or ovary pubescence or on the morphology of the calyx. In many cases the type specimens are clearly distinct from each other, but while analyzing all the populations across the entire geographical range, it becomes evident that most of the variation falls within a continuum, which makes it impossible to recognize all of these forms as separate species. Different authors (Cogniaux, 1888; Gleason, 1931b; Macbride, 1941; Wurdack, 1973b, 1980; Wurdack & Renner, 1993; Vasquez, 1997; Michelangeli, 2001b) have addressed this problem, seldom arriving at similar conclusions as to which species should be recognized. The most detailed of these analyses was performed by Gleason (1931b), who took into account the shape and pubescence of the apex of the ovary and the shape and pubescence of the outer teeth calyx. Twelve possible combinations of calyx and ovary characters were outlined by Gleason (1931b), although he did not observe all of them. However, in reviewing live populations and herbarium collections for this monograph, I found all of them to occur in natural populations. Many of these forms correspond to described names. In general, individuals growing in the sun tend to be less pubescent than individuals growing in the shade. Likewise, individuals in wetter areas or soils, tend to be more pubescent that in dryer areas. This variation can occur even within individuals. During the course of this study, two branches of the same individual, one growing in the shade and one in the sun, were keyed out to different “species” due to the variation in pubescence of the hypanthium and ovary (i.e. T. guianensis and T. occidentalis). The type of T. acuminata is labeled as coming from Ecuador, but Bentham’s description cites it as coming from “Colombia and Isle of Gorgana” (sic). There is a specimen at K (Hooker Herbarium) of Barclay annotated as from “Island of Gorgana”, which seems to be annotated by Bentham. Of all the forms here considered synonyms of T. guianensis, T. formicaria seems to be the most distinct one, due to its dense and long pubescence on vegetative parts as well as the hypanthium, and perhaps could be considered a separate taxon. However, the distribution of specimens with the typical pubescence of T. formicaria falls within the range of distribution of specimens with characters that match the type of T. guianensis. Moreover, in this area (central Brazil) a considerable number of the specimens examined exhibited a continuum of density and size of pubescence between T. guianensis and T. formicaria.

  • Floras and Monographs

    Tococa guianensis Aubl.: [Article] Michelangeli, Fabián A. 2005. (Melastomataceae). Fl. Neotrop. Monogr. 98: 1-114.

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