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Trees, monoecious. Leaves in spirals; stipules fully amplexicaul, free; blade entire or pinnately incised, innately veined. Inflorescences unisexual, in the leaf axils or on the main branches and the trunk, usually with bracts. Staminate inflorescences clavate to subspicate; perianth tubular; stamens 1. Pistillate inflorescences globose to ellipsoid capitate, flowers numerous; stigmas 1-2, subulate to spathulate. Infructescences large, with a firm outer layer and a soft layer containing the fruits; seed large, without endosperm, cotyledons equal and thick.


Asian mainland present, Malaysia present, all over the tropics cultivated
Asian mainland and Malaysia: 47 species, 2 of them cultivated all over the tropics.


Vessels diffuse, solitary (45-80%) and in short radial multiples and irregular clusters of 2-4, round and oval, 2-6 per sq. mm, diameter 160-310 μm (in the Guianas 100-150μm for A. heterophyllus, and 180-230μm for A. altilis). Vessel-member length: 350-630 μm. Perforations simple. Inter- vascular pits alternate, round, polygonal and occasionally slightly oval, 9-13 μm. Vessel-ray and vessel-parenchyma pits larger, half-bordered, the borders sometimes reduced. Thin-walled tyloses common, but occasionally absent. White deposits sometimes present.
Rays uniseriate and 3-5-seriate, 3-6 per mm, up to 60-1200 μm high. Heterogeneous, composed of procumbent cells, except for the uniseriate margins of 1-2(5) rows of square and/or upright cells. Occasionally few sheath cells present. Radial latex tubes common.
Parenchyma aliform with short to long wings, occasionally confluent, and sporadically in short wavy bands. Strands of 3-4 cells.
Fibres non-septate, lumen 7-25 μm, walls 2-4 μm. Pits simple, small, confined to the radial walls. Gelatinous fibres present or absent. Length: 1170-1950 μm. F/V ratio: 2.3-3.9.
Vitreous silica common, in the fibres or in the vessels, often enveloping the tyloses. Axial latex tubes sometimes present.


This genus is introduced into the Guianas. No samples from this area are available. The description is based on material from the natural area of origin (ter Welle et al., 1986B).