Cuervea
Description
Lianas, shrubs or slender trees, glabrous; branchlets subterete to quadrangular. Inflorescences axillary, laxly flowered. Flowers large for the family (8-)10-18 mm diam.; sepals 5; petals 5; disk erect, short-cylindric or flattened, margin entire to minutely crenulate; stamens 3, suberect, filaments ligulate, strongly widened towards the base, anthers transversely ellipsoid, dehiscing by wide, transverse, confluent clefts; ovary trigonous, deeply sulcate, gradually tapering into the short, truncate style, locules 3, ovules 4-8 per locule, stigmas 3, opposite the stamens. Fruits consisting of 3, convex, distinct, separately attached, conspicuously veined mericarps; seeds erect from the base, embryoniferous part coriaceous, ellipsoid, affixed by a basal, thin-coriaceous stipe or reduced wing.
Distribution
Africa present, Guianas present, Neotropics present, S Mexico present, Southern America: Paraguay (Paraguay present), central Brazil present
2 species in Africa; 3 species in the Neotropics ranging from S Mexico and the West Indies to Central Brazil and Paraguay, 1 of which occurs in the Guianas.
Wood
Growth rings present, border formed by a narrow band of unlignified cells in the wide rays and by a delatation of the wide rays.
Vessels diffuse, solitary, 8(5-11) per sq. mm, roundish, marked diffe- rence in diameter, narrow vessels 30-60μm, wider ones 120-260 μm. Vessel-member length: 770(500-1140) μm.Perforations simple. Inter- vascular pits alternate, few, elongate, 5-6 μm. Vessel-ray pits as the intervascular pits.
Rays uni- and multi-seriate, the latter 4-18 cells wide; 5-10 per mm, of which 2-4 wide. The uniseriates heterogeneous with square and upright cells, 1-10 cells high; the multi-seriates homogeneous, the cells pro- cumbent, the rays up to 300 μm wide, and over 650 cells (= 8 mm) high. Numerous rhombic crystals in the procumbent cells of the wide rays, few in upright cells of the uniseriates. Cells of the wide rays partly with unlignified walls.
Parenchyma scarce, vasicentric, as an often interrupted 1 cell wide band. Strands of 3-10 cells.
Ground tissue of fibre-tracheids and fibres. Fibre-tracheids lumen 10-15μm, walls 3-4 μm. Small bordered pits on both radial and tangential walls. Fibres mostly septate, lumen of 15-20μm, walls 1-2μm, minute bordered pits on both radial and tangential walls.
Arranged in numerous one cell wide bands. Length of the fibre-tracheids 1310 (880-1700) μm. FIV ratio: 1.60-1.72.
Vessels diffuse, solitary, 8(5-11) per sq. mm, roundish, marked diffe- rence in diameter, narrow vessels 30-60μm, wider ones 120-260 μm. Vessel-member length: 770(500-1140) μm.Perforations simple. Inter- vascular pits alternate, few, elongate, 5-6 μm. Vessel-ray pits as the intervascular pits.
Rays uni- and multi-seriate, the latter 4-18 cells wide; 5-10 per mm, of which 2-4 wide. The uniseriates heterogeneous with square and upright cells, 1-10 cells high; the multi-seriates homogeneous, the cells pro- cumbent, the rays up to 300 μm wide, and over 650 cells (= 8 mm) high. Numerous rhombic crystals in the procumbent cells of the wide rays, few in upright cells of the uniseriates. Cells of the wide rays partly with unlignified walls.
Parenchyma scarce, vasicentric, as an often interrupted 1 cell wide band. Strands of 3-10 cells.
Ground tissue of fibre-tracheids and fibres. Fibre-tracheids lumen 10-15μm, walls 3-4 μm. Small bordered pits on both radial and tangential walls. Fibres mostly septate, lumen of 15-20μm, walls 1-2μm, minute bordered pits on both radial and tangential walls.
Arranged in numerous one cell wide bands. Length of the fibre-tracheids 1310 (880-1700) μm. FIV ratio: 1.60-1.72.