95. Guatteria megalocarpa Maas & Westra, sp. nov. — Fig. 48; Map 20

Monocarpiis maximis, ellipsoideis, foliis verruculosis, seminibus rugosis facile recognoscenda. —

Typus: Espinosa & Coba 535 (holo U; iso CR, MO), Ecuador, Pastaza, Cantón Pastaza, Pozo petrolero Namoyacu de UNOCAL, 30 km S of Curaray, 290 m, 13–30 Nov. 1990.

Tree 10 m tall, c. 10 cm diam; young twigs sparsely covered with appressed hairs, soon glabrous. Leaves: petioles 15– 20 mm long, 1.5–3 mm diam; lamina elliptic, 15–20 by 6–8 cm (leaf index 2.3–2.8), chartaceous to thinly coriaceous, sparsely to rather densely verruculose, more or less shiny, brownish green above, pale brown below, glabrous above, sparsely covered with appressed, whitish hairs mostly on veins below, base obtuse to rounded, the extreme base shortly attenuate into the petiole, apex acuminate (acumen 10–15 mm long), primary vein flat to slightly impressed above, secondary veins distinct, 13–15 on either side of primary vein, slightly raised above, shortest distance between loops and margin 2–4 mm, tertiary vein raised above, reticulate. Flowers only seen in fruiting stage, fruits solitary on leafless branchlets, fruiting pedicels (one complete seen) c. 35 mm long, 2–3 mm diam, glabrous, articulated at c. 0.1 from the base, bracts fallen, no scars visible anymore. Monocarps 10–15, dark green in vivo, dark brown in sicco, ellipsoid, 20–23 by 13–15 mm, sparsely covered with appressed hairs to glabrous, apex rounded, wall 1.5–2 mm thick, stipes 12–20 by 2 mm. Seed ellipsoid, c. 21 by 13 mm, rugose, raphe impressed.

Distribution — Ecuador (Pastaza).

Habitat & Ecology — In primary, non-inundated forest, on red soil. At an elevation of c. 290 m. Flowering: unknown; fruiting: November.

Vernacular name — Ecuador: Heñetangueme (Huaorani name) (S. Espinoza & Coba 535).

Note — The single collection known to us so far was listed as ‘sp. indet.’ in the revision of sect. Mecocarpus (Maas & Westra 2011). Despite its incompleteness we see sufficient reason for formally describing it as a new species now. Guatteria megalocarpa is quite well characterized by the conspicuously large and ellipsoid monocarps, not matched in any other species of this section. It seems to come closest (also when following the key in the paper cited) to G. blepharophylla, but differs from that by the much longer pedicels, and by the monocarps, which, although of comparable length, are relatively broader (described here as ‘ellipsoid’ vs ‘narrowly ellipsoid’ in G. blepharophylla). The seeds in G. megalocarpa are evenly rugose, as contrasted to the seeds in G. blepharophylla, which tend to be longitudinally and/or transversely grooved.