Hippocratea
Description
Usually lianas, with long twining branches, young parts puberulent; branchlets mostly opposite. Inflorescences terminal and axillary, many-flowered, cymosely paniculate or corymbose, often with 1-2, few-flowered branchlets in each dichotomy; flowers solitary or in cymes at the end of the branchlets, or arranged laterally along those. Sepals 5; petals 5, spreading; disk fleshy, cushion-like to truncate-conical, puberulent without; stamens 3, suberect to reflexed, filaments often adnate to upper margin of disk, anthers transversely ellipsoid, dehiscing by transverse, confluent clefts; ovary trigonous, immersed in the disk, ovules 4-6 per locule, style subulate, stigmas inconspicuous. Fruits 1-3 per infructescence, consisting of 3 dry, divergent, flattened, leathery mericarps, attached to a swollen receptacle. Mericarps dehiscing along an inconspicuous median suture; seeds affixed by a conspicuous basal, membranous wing.
Distribution
Africa present, Neotropics present, tropics and subtropics present
In the tropics and subtropics; 2 species in Africa, 1 in the Neotropics.
Wood
Growth rings faint, due to 4-6 rows of radially compressed fibres. Vessels diffuse, almost exclusively solitary, 10(5-15) per sq. mm, round to oval, diameter of two sizes: 40-80 μm and 120-250 μm, the large vessels prevail. Vessel-member length: 750(450-1100) μm. Perforations simple. Intervascular pits alternate, elongate, 4-5 μm, the slits often confluent. Vessel-ray pits similar, crowded. Vasicentric tracheids occasionally present.
Rays uni- and multiseriate, the uniseriates few, the multi-seriates 3-14(20) cells wide; 5 per mm. Heterogeneous, the middle part mainly of procumbent cells, square and upright cells as sheath cells and at the margins, but also irregularly scattered among the rows of procumbent cells, up to 300 μm wide and over 750 cells(= 12 mm) high. Rhombic crystals present. Occasionally a few cells non-lignified. Parenchyma scarce, narrow vasicentric or scanty paratracheal and apotracheal as few isolated strands. Strands of 6-15 cells.
Ground tissue of fibre-tracheids and septate and non-septate fibres intermingled. Fibre-tracheids lumen 12-16 μm, walls 4-6 μm, numerous small bordered pits on both radial and tangential walls. Septate and non-septate fibres with a lumen of 18-20 μm, walls 2.5-3 μm. Pits simple, mainly on radial walls; occasionally a chain of rhombic crystals present in septate fibres. Length of fibre-tracheids: 1430(1060-1950) μm. F/V ratio: 1.84.
Rays uni- and multiseriate, the uniseriates few, the multi-seriates 3-14(20) cells wide; 5 per mm. Heterogeneous, the middle part mainly of procumbent cells, square and upright cells as sheath cells and at the margins, but also irregularly scattered among the rows of procumbent cells, up to 300 μm wide and over 750 cells(= 12 mm) high. Rhombic crystals present. Occasionally a few cells non-lignified. Parenchyma scarce, narrow vasicentric or scanty paratracheal and apotracheal as few isolated strands. Strands of 6-15 cells.
Ground tissue of fibre-tracheids and septate and non-septate fibres intermingled. Fibre-tracheids lumen 12-16 μm, walls 4-6 μm, numerous small bordered pits on both radial and tangential walls. Septate and non-septate fibres with a lumen of 18-20 μm, walls 2.5-3 μm. Pits simple, mainly on radial walls; occasionally a chain of rhombic crystals present in septate fibres. Length of fibre-tracheids: 1430(1060-1950) μm. F/V ratio: 1.84.