Oxandra euneura Diels — Plate

Junikka, L., Maas, P. J. M., Maas-van de Kamer, H. & Westra, L. Y. Th., 2016, Revision of Oxandra (Annonaceae), Blumea 61 (3), pp. 215-266 : 227-229

5. Oxandra euneura Diels — Plate 1f, g; Map 3

Oxandra euneura Diels (1927) 173. — Type: Tessmann 5320 (holo B), Peru, Loreto, ‘ Oberes Amazonas-Gebiet’, Lower Río Itaya , Soledad , 110 m, June 1925.

Tree or shrub 2–15 m tall, 3–40 cm diam; young twigs rather densely covered with appressed or erect hairs, soon glabrous. Leaves: petiole 1–5 mm long, 2–3 mm diam; lamina narrowly ovate to narrowly obovate, 10–24 by 3–9 cm (leaf index 2.5–3.7), chartaceous, densely verruculose above and below, shiny and greyish or brownish green above, brownish green below, glabrous above, sparsely covered with appressed hairs to glabrous below, base acute, obtuse, to oblique and slightly cordate, apex acuminate (acumen 10–20 mm long), primary vein raised above, secondary veins distinct, 10–14 on either side of primary vein, raised above, but seemingly impressed due to the laminar tissue bulging upward, angle of secondary veins with primary vein 65–80°, united into a distinct marginal vein, smallest distance between marginal vein and margin 3–5 mm, tertiary veins slightly raised above, reticulate. Flowers in 1–2(–4)-flowered inflorescences; pedicels 3–4 mm long, 0.5–1 mm diam, 4–8 mm long in fruit, rather densely to sparsely covered with appressed hairs; bracts 3–5, depressed ovate, 0.5–1.5 mm long, outer side rather densely to sparsely covered with appressed hairs; flower buds ellipsoid to ellipsoid-oblongoid; sepals broadly to shallowly ovate-triangular, 1–1.5 by 1–2 mm, outer side rather densely covered with appressed hairs; petals white in vivo, elliptic to narrowly so, 6–8 by 2–3 mm, outer side rather densely covered with appressed and erect hairs; stamens 6–15, 2–3 mm long, apex of connective narrowly triangular; carpels ≤ 6. Monocarps 1–6, green, maturing pinkish red to black in vivo, black in sicco, ellipsoid to narrowly ovoid-oblongoid, strongly narrowed towards the apex, sometimes more or less curved, 10–30 by 6–10 mm, rather densely to sparsely covered with appressed hairs to glabrous, apex apiculate (apiculum 2–2.5 mm long) and often hard-pointed, wall 0.2–0.3 mm thick, stipes c. 1 by 1–1.5 mm. Seed narrowly oblongoid-ellipsoid, 10–30 by 6–9 mm, pale brown, surface transversely striate, ruminations spiniform or peg-shaped.

Distribution — Colombia (Amazonas, Caquetá, Vaupés), Venezuela (Amazonas), Ecuador (Napo, Sucumbios), Peru (Loreto), Brazil (Amazonas, Rondônia), Bolivia (La Paz).

Habitat & Ecology — In periodically inundated (igapó, tahuampa) forests or non-inundated forest, on sandy or clayey soil. At elevations of 0–1000 m. Flowering: all year through; fruiting: all year through.

Vernacular names — Brazil: Pindaípixuna (W. Rodrigues 1006). Colombia: Cueronegro (Wijninga & Quintero 623), Fici-cu (Muinane name, Van Andel 441), Jajobahi hãrãdo jeicobu (= Fishing rod flower, Cubeo name, Madriñán et al. 1182). Peru: Baracaspi (Rimachi Y. 7480), Carahuasca ( Vásquez & Criollo 5786), Espintana (Ellenberg 2907) , Espintana amarilla (Dodson & Torres 2973), Tortuga caspi (Ellenberg 2856), Yahuarachi caspi ( Vásquez et al. 5390, 7994), Yana tortuga (McDaniel & Rimachi Y. 20295).

Uses — Stems used as fishing rods (Madriñán et al. 1182, Colombia); Con el tronco se elaboran varas para pescar, ca- bos para hachas y palos para bailes ceremonials ( Colombia: Sánchez Sáenz 1997).

Field observations — Flores visitadas por Stafilinidios (Knob et al. 1201, Brazil); Corolla with sweet scent (Maas et al. 8234, Peru).

Note — Oxandra euneura is characterized by having a distinct marginal vein and in having quite elongate and often hard-pointed, sometimes curved monocarps of 10–30 mm long.

Figures

Map 3 Distribution of Oxandra euneura (●), O. guianensis (●) and O. krukoffii (▲).