Maquira
Description
Trees, dioecious or monoecious. Leaves alternate, distichous on the lateral branches; stipules amplexicaul, free; blade entire, pinnately veined. Inflorescences on spurs in the leaf axils, unisexual, discoid-capitate, involucrate. Staminate inflorescences mostly several together, pedunculate; flowers several to numerous, perianth 4-lobed to 4-parted; stamens (3-)4; pistillode absent. Pistillate inflorescences mostly solitary, subsessile or pedunculate; flowers many and free, a few and connate, or one; perianth 4-lobed to 4-fid; ovary adnate to the perianth; stigmas 2, tongue-shaped. Fruiting perianth enlarged, fleshy, orange; fruit adnate to the perianth; seed large, without endosperm, cotyledons thick and equal.
Wood
Vessels diffuse, with a slight tendency towards a diagonal arrangement, solitary (40-90%) and in short radial multiples of 2-4, round to oval, 5-17 per sq. mm, diameter 100-155 μm. Vessel-member length: 505-575 μm. Perforations simple. Intervascular pits alternate, round, oval to polygonal, 7-9 μm. Vessel-ray and vessel-parenchyma pits larger and irregularly shaped, half-bordered. Thin-walled tyloses often present.
Rays uniseriate and 3-5-seriate, 6-8 per mm, up to 360-1150 μm high. Heterogeneous, composed of procumbent cells, except for the uniseriate margins of 1-3 rows of square and/or upright cells. Few sheath cells. Radial latex tubes generally present, though sometimes very infrequent. Rhombic crystals sometimes present in the marginal ray cells.
Parenchyma paratracheal, variable, wide to narrow vasicentric- aliform with short wings to confluent and in narrow bands, sometimes wavy. Strands of 3-4 cells. Rhombic crystals very scarce.
Fibres all or partly septate, lumen 5-9 μm, walls 3-5 μm. Pits simple, small, restricted to the radial walls. Gelatinous fibres occasionally present. Length: 1100-1410 μm. F/V ratio: 2.0-2.8.
Vitreous silica sometimes present in the axial parenchyma, rarely also in the vessels and fibres.
Rays uniseriate and 3-5-seriate, 6-8 per mm, up to 360-1150 μm high. Heterogeneous, composed of procumbent cells, except for the uniseriate margins of 1-3 rows of square and/or upright cells. Few sheath cells. Radial latex tubes generally present, though sometimes very infrequent. Rhombic crystals sometimes present in the marginal ray cells.
Parenchyma paratracheal, variable, wide to narrow vasicentric- aliform with short wings to confluent and in narrow bands, sometimes wavy. Strands of 3-4 cells. Rhombic crystals very scarce.
Fibres all or partly septate, lumen 5-9 μm, walls 3-5 μm. Pits simple, small, restricted to the radial walls. Gelatinous fibres occasionally present. Length: 1100-1410 μm. F/V ratio: 2.0-2.8.
Vitreous silica sometimes present in the axial parenchyma, rarely also in the vessels and fibres.
Notes
A recent sterile collection (Sabatier 1533) made in French Guiana, Montagne de Nouragues, near Arataye River, suggests the occurrence of M. calophylla (Poepp. & Endl.) C.C. Berg . This species resembles M. guianensis in its leaf venation, but is distinct from the latter in the smaller staminate inflorescences (less than 0.8 cm in diam.) and in the pistillate inflorescences, which have only one or a few, connate flowers.