Tococa macrosperma Mart.

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Tococa macrosperma Mart.

  • Primary Citation

    Nov. Gen. Sp. Pl. (Martius) 3: 148, tab. 279. 1829

  • 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: Brazil. Amazonas: Martius s.n. (Holotype, G).

    Description: Shrub, to 0.5-2.0 (-3.0) m tall. Stems with a mix of glandular and non-glandular setae, the trichomes 2.0-3.0 mm long, occasionally barbed, persistent, the nodes glabrous, occasionally developing adventitious roots near the base of the stems. Petioles 0.3-1.5 (-3.5) cm long, with a mix of glandular setae, occasionally with barbed trichomes. Leaves anisophyllous, the large ones elliptic to oblong, 8-22 (-29) x 4-13 cm, the smaller ones oblong to lanceolate, 2-6 x 1-3 cm, apex shortly acuminate, base cordate, adaxial surface adpressed-setose, abaxial surface sparsely adpressed-setose, the primary and secondary veins densely glandular and non-glandular setose, light green, with 2(-3) pairs of secondary veins, shortly plinervate, membranaceous, ciliate-serrulate; domatia present in the larger leaves, rarely in the smaller leaves, 1/2 to completely immersed in the leaf blade, scrotiform, 1.0-2.5 (-3.5) x 0.8-2.2 (-3.0) cm, with trichomes up to 12 mm long. Flowers solitary or in dicasia, initially terminal, but quickly becoming axillary by overgrowth of the lateral meristem, often subtended by two small leaves (up to 3 cm long). Flowers on pedicels 1.0-2.0 mm long, not flared at the apex, not subtended bracts; hypanthium broadly conical, but quickly becoming globose, 3.5-4.5 mm long, glandular setose, occasionally the trichomes densely barbed; sepals completely connate or nearly so, 2.0-3.0 mm long, glandular pubescent, calyx teeth connate, forming a skirt around the hypanthium, 2.0-2.5 mm long, terminated in one or more glandular setae, up to 4 mm long; the ring inside the torus glabrous. Petals 6, oblong to ovate, 11-22 (-25) x 4.5-7.0 mm, base oblong to slightly attenuate, apex emarginate, occasionally with caducous sessile glands in the margins near the base, rarely with one or more short glandular setae at the apex, the surface smooth, bright pink to dark red in the abaxial surface, becoming white after anthesis, white in the adaxial surface. Stamens all of the same size, the filaments 5.0-8.0 mm long, glabrous; anthers yellow; the connective with or without a dorsal-basal blunt tooth; thecae 3.0-4.0 mm long, opening by a ventrally inclined pore. Ovary 3-locular, 2/3 inferior, the superior portion conical, with out a ring around the style, the apex with a corona of glandular setae; style glabrous, 8-11 mm long; stigma capitate, 1.5-2.0 mm wide. Fruits globose, 4.5-8.0 mm long, black, glandular setose. The seeds not evident through the pericarp, truncate-obovate, 1.2-2.8 mm long, without capitate trichomes in the raphal area, without sculpturing, anticlinal walls straight, periclinal walls flat, boundaries between periclinal walls raised. Chromosome number n= unknown.

    Habitat and Distribution: S Colombia and Venezuela, NE Peru and N Brazil. Growing in the understory of tierra firme forests, occasionally in the savanna-forest ecotone, from 50 to 1100 m.

    Ecology: Tococa macrosperma is usually found in the understory of the forest, and it is usually associated with timid ants of the genera Crematogaster and Pheidole. Plants found above the 700 m often do not have ants inhabiting the domatia (Michelangeli, 2000b).

    Taxonomy and Systematics: Tococa macrosperma was originally described by Martius (1832) in the genus Tococa, and on the immediately following page of the same publication segregated it into its own genus, on the basis of its unique calyx and large seeds. Several researchers have agreed that Myrmidone is closely related to Tococa and even that it is solely a segregate (see discussion on the phylogenetic relationships in Michelangeli 2005). Wurdack (pers. comm.) kept Myrmidone as a separate genus not only on the basis of the calyx and seeds, but also due to the lack of the dorsal tooth in the anther connective. However, during the course of this study it became evident that T. macrosperma is polymorphic for this character, and therefore should not be used as a diagnostic character to separate the two genera. Additionally, the morphological cladistic analysis presented here shows that T. macrosperma is nested within Tococa sensu stricto. The description of Hormocalyx hirsutus notes that the ovary is 2 locular, but all the specimens examined during this study show 3-locular ovaries. The differences between Myrmidone lanceolata and T. macrosperma involve characters that are highly variable across populations, and does not support the recognition of separate taxa. Tococa macrosperma is closely related to T. rotundifolia with which it shares extreme anisophylly and domatia immersed in the leaf blade. Additionally, these two species have pseudo-axillary inflorescences with one or two flowers and bright red petals. Tococa macrosperma can be distinguished by the larger leaves and the connate calyx teeth that form a skirt around the hypanthium. Tococa macrosperma is often confused with different species of the genus Maieta Aublet. Even though these two taxa are superficially similar, they can be easily distinguished by the floral characters given above. Additionally, the anthers of Maieta are incurved with the thecae extending basally beyond the point of attachment with the connective. Vegetatively, they can be distinguished by the leaf base and the shape of the domatia; in T. macrosperma the leaves are cordate and the domatia are scrotiform, while in Maieta the leaves are attenuate at the base with the domatia narrowly elliptic to fusiform and completely immersed in the leaf blade. The leaves of T. macrosperma are used by Baré Amerindians in southern Venezuela to prepare a tea that is given to their pregnant women if a baby girl is desired.

  • Floras and Monographs

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