Oxandra macrophylla R.E.Fr.

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 : 239

12. Oxandra macrophylla R.E.Fr. — Fig. 12, 13a; Map 7

Oxandra macrophylla R.E.Fr. (1931) 173. — Type: Killip & Smith 28752 (holo B; iso NY,US), Peru, Loreto, Santa Rosa , Lower Río Huallaga,below Yurimaguas , 135 m, Sept. 1929.

Shrub or tree 3–13 m tall, 4–13 cm diam; young twigs densely covered with erect, brown hairs, soon glabrous. Leaves: petiole 1–5 mm long, 2–3 mm diam; lamina ovate to obovate or narrowly so, 17–26 by 6–12 cm (leaf index 2.1–3.4), chartaceous, densely verruculose above and below, dull and grey to brown-

Map 7 Distribution of Oxandra macrophylla (●) and O. mediocris (●).

ish green above, greyish brown to brown below, glabrous, but primary vein densely covered with erect hairs to c. 2 mm long above, rather densely to sparsely covered with erect and appressed hairs below, base acute to slightly cordate, apex acuminate (acumen 15–20 mm long), primary vein impressed above, secondary veins distinct, 15– 20 on either side of primary vein, slightly raised above, angle of secondary veins with primary vein 65–80°, smallest distance between loops and margin 2 – 5 mm, tertiary veins flat to slightly raised above, reticulate to percurrent. Flowers in 1–2-flowered inflorescences; flowering pedicels not seen, fruiting pedicels 3–5 mm long, 1–2 mm diam, glabrous; bracts 5–6, depressed ovate, 1.5–2 mm long, outer side rather densely covered with appressed hairs to glabrous; flower buds ellipsoid; sepals depressed ovate, 1.5–2 by 1.5–2 mm, outer side sparsely to rather densely covered with appressed hairs; petals white in vivo, elliptic to obovate, 4–8 by 2–5 mm, outer side glabrous; stamens 5–18, 1.5–2.5 mm long, apex of connective ovate-triangular; carpels ≤ 5. Monocarps 5 –20, colour in vivo not recorded, black in sicco, ellipsoid, 17–20 by 7–9 mm, glabrous, apex apiculate (apiculum <0.5 mm long), wall c. 0.5 mm thick, stipes 3–6.5 by 1–2 mm. Seed ellipsoid, 17–20 by 7–9 mm, brown, surface transversely striate, ruminations spiniform or peg-shaped.

Distribution — Amazonian Brazil (Acre,Amazonas) and Peru (Loreto).

Habitat & Ecology — In non-inundated or periodically inundated (tahuampa, várzea) forest. At elevations of 0– 200 m. Flowering: June; fruiting: May, September, October.

Vernacular name — Peru: Chuchuhuasha mashan (Ll. Williams 4129).

Note — A characteristic of O. macrophylla are the (often) large leaves with an impressed primary vein densely covered with long erect hairs above. In this aspect it is easily distinguished from large-leaved forms of O. xylopioides which lack such hairs and which have, moreover, a leaf base with two tooth-like projections.