Guatteria duodecima Maas & Westra

Maas, P. J. M., Westra, L. Y. T., Guerrero, S. Arias, Lobão, A. Q., Scharf, U., Zamora, N. A. & Erkens, R. H. J., 2015, Confronting a morphological nightmare: revision of the Neotropical genus Guatteria (Annonaceae), Blumea 60 (1), pp. 1-219 : 75

54. Guatteria duodecima Maas & Westra — Map 13

Guatteria duodecima Maas & Westra in Erkens et al. (2008) 483, f. 6; Maas & Westra (2011) 121. — 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 c. 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), charta- ceous, 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, second- ary veins distinct, 13–20 on either side of primary vein, raised above, smallest distance between loops and margin 1–3 mm, tertiary veins raised above, reticulate. 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 to c. 25 mm long, 2–3 mm diam, densely covered with appressed hairs, articulated at 0.2–0.6 from the base, bracts 3–5, soon falling, the upper one 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, maturing brownish yellow in vivo, 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 to 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, rugose, raphe raised.

Distribution — Amazonian Ecuador (Morona-Santiago, Napo, Pastaza, Zamora-Chinchipe), Peru (Cusco, Loreto, Madre de Dios, Pasco, San Martín ), Brazil (Acre), Bolivia (Beni, La Paz, Pando, Santa Cruz).

Map 13 Distribution of Guatteria duckeana (●), G. duodecima (£), G. dura (■), G. elata (P) and G. elegans (u).

Habitat & Ecology — In non-inundated, lowland rain forest to premontane forest, sometimes in periodically inundated forest. At elevations of 150–1800 m. Flowering: throughout the year; fruiting: May to November.

Vernacular names — Bolivia: Oyshobo (Yuracare name) ( Thomas & Agustin 2024), Piraquina ( Thomas & Agustin 2024). Peru: Atzmiriqui (D.N. Smith 5290).

Field observations — Flowers of G. duodecima reportedly have an apple-like odor (Korning & Thomsen 47656).

Notes — Guatteria duodecima at first glance can be distin- guished by relatively narrow and verruculose leaves, usually narrowed towards both ends, and which are densely to rather densely covered with appressed, almost silvery hairs on the lower side. Other distinctive features are the shortly pedicellate flowers, and monocarps that are always longer that the stipes. The lower side of the leaves is mentioned as having a silvery shine (Chatrou et al. 25).