Tetrameranthus macrocarpus R.E.Fr.

Westra, Lubbert Y. T. & Maas, Paul J. M., 2012, Tetrameranthus (Annonaceae) revisited including a new species, PhytoKeys 12, pp. 1-21 : 11-13

Tetrameranthus macrocarpus R.E.Fr. Map 2

Tetrameranthus macrocarpus Arkiv för Botanik Ser. 2, 3(18): 603, plate 4. 1957.

Type.

Schultes & Cabrera 17091 (holotype S; isotypes COL, GH, U), Colombia, Vaupés: Río Piraparaná, Raudal Coro ( “Koro”), 30 August 1952.

Description.

Tall tree, young twigs and petioles densely to rather densely covered with stellate hairs>0.5 mm long. Leaves: petioles 20-30 mm long, 3-4 mm diam., slightly thickened toward the base; lamina elliptic to obovate to narrowly so, 14-20 by 5-8 cm (index 2-2.9), coriaceous, glabrous above, rather densely to sparsely covered with stellate hairs on large veins, otherwise glabrous below, base acute to attenuate, apex acuminate (acumen 5-20 m long), primary vein impressed above, secondary veins 9-11 on either side of primary vein, impressed above, loop-forming, shortest distance between loops and margin 1-2 mm, or not loop-forming, tertiary veins flat and inconspicuous above, percurrent to reticulate. Inflorescences 1-flowered; peduncles c. 5 mm long, 2-2.5 mm diam., fruiting peduncles to c. 5 mm diam.; bracts 4, triangular to narrowly triangular, 2-3 mm long, outer side densely covered with stellate hairs, falling after flowering; pedicels 25-30 mm long, c. 2 mm diam., fruiting pedicels to c. 35 mm long, peduncles and pedicels densely covered with stellate hairs, becoming glabrous. Flowers: color not mentioned; sepals broadly triangular-ovate, connate just at the base, 3-4 mm long, outer side densely covered with stellate hairs; outer petals elliptic, 25-30 mm long, 12-15 mm wide, base attenuate into a more or less distinct claw, apex acute to obtuse, callus area at inner base to c. 5 mm long, inner petals similar to outer petals, 20-25 mm long, outer side of petals densely covered with stellate hairs; stamens c. 3 mm long, connective shield with conical prolongation (fide Fries 1957). Monocarps 1 - 2, green, probably maturing yellow in vivo, brown in sicco, ellipsoid or oblongoid, with (2-seeded forms) or without oblique constriction, apex rounded, to c. 60 (1-seeded) or c. 80 by 35 mm (2-seeded). Seeds 1-2 per monocarp, to c. 35 by 28 mm.

Distribution.

Colombia ( Vaupés). Only known from the type collection.

Habitat and ecology.

Not recorded.

Note.

This single collection of Tetrameranthus macrocarpus seems to come quite near some forms of the variable Tetrameranthus duckei . It is distinct from the latter primarily by the larger fruit. Moreover, it is reported to be a tall tree (without more precise indication of size), whereas reports for Tetrameranthus duckei indicate a medium-sized tree to about 12 m tall so far. Nevertheless one might wonder if Tetrameranthus macrocarpus is merely an extreme form of Tetrameranthus duckei , but more extensive collecting in the western Amazon region is needed before this question could be answered.

Figures

Map 2. Distribution of Tetrameranthus globuliferus Westra (○), Tetrameranthus laomae D. R. Simpson (□), Tetrameranthus macrocarpus R. E. Fr. (◉), and Tetrameranthus umbellatus Westra (◆).