Poraqueiba

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Poraqueiba

Description

Tall trees. Leaves entire, glabrescent. Inflorescences axillary panicles, branched from base. Flowers small, perfect, sessile or subsessile, articulate below the calyx, subtended by 3 imbricate sericeous bracts; calyx fleshy, sericeous, with 5 imbricate lobes; petals free, fleshy, margins incurved, apex inflexed, midrib prominent, longitudinally furrowed and partly pubescent inside; stamens 5, glabrous, filaments fleshy, flattened, broadened at middle, abruptly narrowed towards anthers, anthers oblong, basifixed, connective broad, tapering into inflexed top, thecae lateral on connective, laterally dehiscent; ovary globose, glabrous, 1-celled, style short, stigma capitate. Fruit a drupe, ovoid to ellipsoid, somewhat oblique, mesocarp fleshy, containing oil, endocarp woody; seed with embryo minute, curved or nearly straight.

Distribution

Guianas: present Southern America:, Panamá (Panamá present); Peru (Peru present)
3 species in Panama, Peru, and Brazil, 1 of which in the Guianas.

Wood observation species

P. guianensis

Wood

Vessels diffuse, solitary, round to oval, 7-10(5-12) per sq. mm, diameter 115-150(90-160) μm. Vessel-member length: 1896-2038(1176-2558) μm. Perforations scalariform, 12-25(19-31) bars per plate. Inter- vascular pits alternate, round, 5-6 μm in diameter. Vessel-ray pits round, elongate and scalariform. Vessel-parenchyma pits elongate. Tyloses sometimes present.
Rays in two types, 6-7 per mm, uni-biseriate, over 2300 μm (= 100 cells) high, heterogeneous, composed of square and procumbent and some upright cells; and multiseriate, 11-15 cells wide, over 7500-12000 μm (=over 250-400 cells) high, heterogeneous, composed of procumbent and square cells. Rhombic crystals common.
Parenchyma apotracheal in short, wavy, tangential bands, one cell wide, and diffuse, and some scanty paratracheal cells. Strands 8-16 cells. Rhombic crystals very scarce.
Fibres non-septate, thick-walled, lumen 5-8 μm, walls 10-13 μm. Pits bordered, on radial and tangential walls, 6-10 μm. Length: 2665(2087-3469) μm. F/V ratio: 1.40-1.45.