Hernandia
Content
Description
Trees, rarely shrubs, in general evergreen (rarely deciduous). Leaves simple (rarely 3-5-lobed), often peltate, cystoliths absent. Inflorescences consisting of a branched axis and flowers in cincinni; peduncles elongate (rarely short); cincinni with 3 flowers (rarely 2 or 1): 2 (1) lateral male flower(s) and 1 central, subsessile female flower (rarely bisexual) on branches of the first (rarely second) order, or on main axis; upper parts of branches somewhat tawny or white pubescent, rarely glabrous; bracts generally present; bracteoles of male flowers 4, ± equal, free, partly including flower buds from cincinnus, bracteoles of female flower 2, connate, forming fleshy, campanulate cupule. Flower buds ovoid, rarely globose. Flowers bisexual or unisexual, then monoecious, rarely dioecious; perianth segments free, minutely pubescent on both sides, outer segments quincuncial or imbricate, inner segments narrower and imbricate or valvate. Male flowers: 6-12 perianth segments; stamen filaments short, each with 2 yellow, somewhat stalked, glandular appendages, free or united; pollen 90-160 μm, spinose; staminodes absent; pistil rudimentary. Female flowers: 8-12 perianth segments; stamens absent, glands 4-5(-10-12), free or connate; ovary laterally somewhat compressed, style sigmoid or straight, moderately thick or thinner towards base, stigma mostly diagonally placed, large, fleshy, margin fimbriate. Drupes black, ovoid or ellipsoid, ribbed/striped, included in cupule; cotyledons free and rather thick, or connate and ruminate. Dispersal of fruits zoöchorous or hydrochorous.
Distribution
Guianas present, Indomalaysia present, Pacific islands present, Pantropical present, Southern America, West Africa present, coastal regions in Central America present
Pantropical, 26 species; most frequent in coastal regions in Central America, the Guianas, West Indies, West Africa, Indomalaysia, Pacific Islands.
Wood
Growth rings usually present, boundaries indicated by a few to several rows of flattened fibres, occasionally by a more or less continuous band of parenchyma.
Vessels diffuse, for the greater part solitary (50-80 %), the remainder in radial pairs, seldom in longer chains or in clusters, outline round to oval, 160-250 μm wide; number very scarce, 1.5 (0-3) per mm². Vessel member length 580 (300-840) μm. Intervessel pits large, alternate, 14-17 μm with included, wide apertures. Vessel-ray pits and vessel-parenchyma pits of two types, similar to the intervessl pits and very large and irregular-shaped, with strongly reduced borders.
Rays 1-4-seriate, uniseriates rather scarce; 4 (2-5) per mm; almost homocellular, marginal cells of the same height as the procumbent cells; multiseriates usually with short uniseriate margins; height up to 600 μm (18 cells).
Parenchyma mainly paratracheal, ranging from vasicentric to aliform and aliform-confluent, also some diffuse and in aggregates; strands of 2-4 cells.
Fibres non-septate, thin-walled (2-2.5 μm), diam. 23-25 μm. Intercellular cavities obvious. Pits minute, bordered, in radial walls. Length of fibres 1272 (990-1450) μm. F/V ratio 2.2.
Vessels diffuse, for the greater part solitary (50-80 %), the remainder in radial pairs, seldom in longer chains or in clusters, outline round to oval, 160-250 μm wide; number very scarce, 1.5 (0-3) per mm². Vessel member length 580 (300-840) μm. Intervessel pits large, alternate, 14-17 μm with included, wide apertures. Vessel-ray pits and vessel-parenchyma pits of two types, similar to the intervessl pits and very large and irregular-shaped, with strongly reduced borders.
Rays 1-4-seriate, uniseriates rather scarce; 4 (2-5) per mm; almost homocellular, marginal cells of the same height as the procumbent cells; multiseriates usually with short uniseriate margins; height up to 600 μm (18 cells).
Parenchyma mainly paratracheal, ranging from vasicentric to aliform and aliform-confluent, also some diffuse and in aggregates; strands of 2-4 cells.
Fibres non-septate, thin-walled (2-2.5 μm), diam. 23-25 μm. Intercellular cavities obvious. Pits minute, bordered, in radial walls. Length of fibres 1272 (990-1450) μm. F/V ratio 2.2.