Guatteria duodecima Maas & Westra

4. Guatteria duodecima Maas & Westra View in CoL

Guatteria duodecima Maas & Westra in Erkens et al. (2008) 483, f. 6. — Type: Zak & Espinoza 4811 (holo U; iso AAU, F, K, MO, WU), Ecuador, Pastaza, Cantón Pastaza, Pozo petrolero ‘Ramirez’, 20 km S of Curaray , 300 m, 21–28 Feb. 1990.

Guatteria sp. 12 Chatrou et al. (1997) 111.

Tree 5 – 40 m tall, up to 60 cm diam, one specimen reported with steep buttresses; young twigs densely to sparsely covered with appressed hairs, soon glabrous. Leaves: petiole 5 –10 mm long, 0.5 –1 mm diam; lamina narrowly elliptic to narrowly oblong-elliptic, 8–15 by 2 – 5 cm (leaf index 2.7– 4.4), chartaceous, densely to rather densely verruculose, greyish to brown above, brown to greenish brown below, glabrous or sparsely covered with appressed hairs above, densely to rather densely covered with appressed, white, long hairs (sericeous) below, base attenuate, sometimes acute, apex acuminate (acumen 5 –10 mm long), primary vein impressed to flat above, secondary veins distinct, 13– 20 on either side of primary vein, raised above, smallest distance between loops and margin 1–3 mm. Flowers in 1–2-flowered inflorescences in axils of leaves or on leafless branchlets; pedicels 5 –10 mm long, 0.5 –1{– 2} mm diam, fruiting pedicels up to 25 mm long, 2 – 3 mm diam, densely covered with appressed hairs, articulated at 0.2– 0.7 from the base, bracts 3 – 5, soon falling, the upper bract 3– 3.5 by 1.5 – 2 mm; flower buds broadly ovoid; sepals free, broadly ovate-triangular, 2 – 4 by 2 – 4 mm, appressed, soon becoming reflexed, outer side densely covered with appressed, white hairs; petals green in vivo, maturing brownish yellow, narrowly oblong-elliptic to narrowly rhombic-ovate, 10–18 by 4 –7 mm, outer side densely covered with appressed, white hairs; stamens c. 1 mm long, connective shield papillate. Monocarps 10– 40, green, maturing purple-black to black in vivo, brown to black in sicco, ellipsoid, 10–18 by 6–12 mm, rather densely covered with appressed hairs, apex rounded or bluntly apiculate (apiculum c. 0.5 mm long), wall 0.5 –1 mm thick, stipes 2 –10 by 1– 2 mm. Seed ellipsoid, 10–13 by 5 –6 mm, shiny brown, foveolate and longitudinally grooved.

Distribution — Ecuador ( Orellana, Pastaza), Peru ( Cuzco, Madre de Dios, Pasco, San Martín), Bolivia ( La Paz) and Brazil ( Acre).

Habitat & Ecology — In non-inundated forest (from lowland rainforest to premontane forest), sometimes in periodically inundated forest. At elevations of 150 – 2200 m. Flowering: throughout the year; fruiting: May to November.

Vernacular names — Bolivia: Piraquina, Oyshobo (Yuracare) ( Thomas & Agustin 2024). Peru: Atzmiriqui.

Note — Guatteria duodecima can at first glance be distinguished by relatively narrow and verruculose leaves which are usually narrowed both toward the base and toward the apex and also are densely to rather densely covered with appressed, almost silvery hairs on the lower side. Other distinctive features of this species are found in the shortly pedicellate flowers and monocarps which are always longer than the stipes.