Pseudolmedia
Description
Trees, dioecious. Leaves alternate, distichous on the lateral branches; stipules fully amplexicaul, free; blade entire, pinnately veined. Inflorescences. on spurs in the leaf axils, discoid-capitate, involucrate, sessile. Staminate inflorescences usually 2-4 together, inner involucral bracts covering the stamens before anthesis; perianth absent; free stamens intermixed with concentrically arranged bracts; pistillode absent. Pistillate inflorescences usually 2 together, uniflorous; perianth tubular, 4-dentate; ovary adnate to the perianth; stigmas 2, filiform. Fruiting perianth enlarged, fleshy, reddish; fruit adnate to the perianth; seed large, without endosperm, cotyledons thick and equal.
Wood
Vessels diffuse, solitary (50-70%) and in short radial multiples of 2-4, round to oval, 8-14 per sq. mm, diameter 70-150 μm. Vessel-member length: 350-540 μm. Perforations simple. Intervascular pits alternate, round, oval to polygonal, 7-10 μm. Vessel-ray and vessel-parenchyma pits larger and irregularly shaped, half-bordered. Thin-walled tvloses often oresent. sclerotic in some samoles of P. laevigata . White deposits sometimes present.
Rays uniseriate and 3-5-seriate, 5-8 per mm, up to 370-1000 μm. Heterogeneous to homogeneous, composed of procumbent cells, with or without 1-2 rows of square marginal cells. Radial latex tubes present, but infrequent and inconspicuous. Rhombic crystals in the marginal ray cells.
Parenchyma paratracheal, confluent to wavy banded, occasionally aliform with short to long wings. Strands of 3-6 cells. Few rhombic crystals.
Fibres all or partly septate, lumen 4-9 μm, walls 3-4 μm. Pits simple, small, restricted to the radial walls. Gelatinous fibres sometimes present. Length: 1100-1550 μm. F/V ratio: 2.4-3.2.
Vitreous silica in most samples, in the vessels, fibres or axial parenchyma.
Rays uniseriate and 3-5-seriate, 5-8 per mm, up to 370-1000 μm. Heterogeneous to homogeneous, composed of procumbent cells, with or without 1-2 rows of square marginal cells. Radial latex tubes present, but infrequent and inconspicuous. Rhombic crystals in the marginal ray cells.
Parenchyma paratracheal, confluent to wavy banded, occasionally aliform with short to long wings. Strands of 3-6 cells. Few rhombic crystals.
Fibres all or partly septate, lumen 4-9 μm, walls 3-4 μm. Pits simple, small, restricted to the radial walls. Gelatinous fibres sometimes present. Length: 1100-1550 μm. F/V ratio: 2.4-3.2.
Vitreous silica in most samples, in the vessels, fibres or axial parenchyma.