Perebea

Primary tabs

Perebea

Description

Trees, dioecious or monoecious. Leaves alternate, distichous on the lateral branches; stipules fully amplexicaul, free; blade entire, pinnately veined. Inflorescences on spurs in the leaf axils, unisexual, discoid-capitate, involucrate. Staminate inflorescences several together, pedunculate, open before anthesis; flowers numerous; tepals 2-4, free or basally connate; stamens 2-4, pistillode absent. Pistillate inflorescences solitary or accompanied by staminate ones, subsessile or pedunculate; flowers several to numerous, free or basally connate; perianth 2-4-lobed to 2-4-fid; ovary free or partly adnate to the perianth; stigmas 2, tongue-shaped or filiform. Fruiting perianth enlarged, fleshy, red(dish); fruit free or partly adnate to the perianth; seed large, without endosperm, cotyledons thick and equal.

Distribution

Guianas present, Neotropics present
Neotropics, 9 species; in the Guianas 2 species.

Citation

Aubl. 1775 – In: Hist. Pl. Guiane: t. 361

Wood observation species

R. guianensis, R. mollis

Wood

Vessels diffuse, with a tendency towards a diagonal arrangement, solitary (40-75%) and in short radial multiples of 2-4, round to oval, 6-12 per sq. mm, diameter 100-160 μm. Vessel-member length: 420-550 μm. Perfora- tions simple. Intervascular pits alternate, round, oval or polygonal, 7-9 μm. Vessel-ray and vessel-parenchyma pits larger and irregularly shaped, half bordered. Thin-walled tyloses occasionally present.
Rays uniseriate and 3-5-seriate, 5-6 per mm, up to 500-900 μm high. Heterogeneous, composed of procumbent cells except for the uniseriate margins of 1-(3) rows of square (upright) cells. Few sheath cells present. Radial latex tubes often present. Rhombic crystals absent or scarce.
Parenchyma paratracheal in generally complete, narrow, aliform- vasicentric rings, often confluent in tangential or diagonal directions over a short distance, the sheaths usually widest on the abaxial side of the vessels. Strands of 4 cells. Rhombic crystals generally lacking, but present in some samples.
Fibres septate, lumen 7-18 pm, walls 2-4 μm. Pits simple, small, confined to the radial walls. Gelatinous fibres occasionally present. Length: 1000-1600 μm. F/V ratio: 2.0-3.4.