Gustavia L.
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Description
Description: Understorey to canopy trees, pachycaul or leptocaul growth form. Leaves scattered or clustered at branch ends on slender or stout twigs, medium to large-sized (10-120 cm long), glabrous; secondary venation reticulate. Inflorescences terminal or axillary, racemose, growth of rachises determinate. Flowers present with leaves, actinomorphic, not markedly fleshy; sepals absent (then calyx entire) or 4-6; petals 6-8 (12 or 18 in G. romeroi), flat at apices; androecium a wide tube, the stamens at margen of tube, curved inward, but not reflexed as in Allantoma, the anthers poricidally dehiscent; ovary 4-6(10)-locular, ovules 7-100 per locule, attached on septum toward apex of locule, the style short, without stylar collar. Fruit indehiscent, remaining on tree or dropping to ground at maturity, usually globose, infrequently cylindric (e.g., G. brachycarpa), the pericarp somewhat soft at maturity, thin or thick. Seeds not winged, infrequently one, usually 2-5 per fruit, not flattened, not embedded in pulp (i.e., seeds easily removed from pulp), the testa glabrous; cotyledons absent, fleshy; embryo macropodial.
Distribution: From Panama into NW South America where it occurs along the coast and in the Andean valleys as far S as Ecuador, throughout Amazonia and the Guianas, and in the northern part of the Brazilian coastal forest. Diversity is greater in NW South America. For example there are only two species in most of the Guianas, one species in the Brazilian coastal forest, and 2 species in eastern Amazonia.
Ecology: Found in both low wet areas and in terra firme habitats. Some species of this genus, e.g., G. superba, do well in disturbed habitats which is unusual for species of this family.
Number of species: There are 40 known species of Gustavia.
Taxonomic notes: A monophyletic genus morphologically defined by poricidal anthers, thin staminal tube with stamens all arising from the same level at the edge of the tube, and fleshy cotyledons. Monophylly of Gustavia is supported by molecular data (Mori et al., 2007). Both pachycaul and leptocaul (e.g., Gusavia sect. Hexapetala and G. speciosa and its relatives) growth forms are found in the genus. The pachycaul species can be unbranched (e.g., G. monocaulis) or sparsely branched (e.g., G. superba and G. augusta).
Etymology: The species epithet honors Gustav III, a former king of Sweden (1746-1792).
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Floras and Monographs
Gustavia L.: [Article] Mori, S. A. & Lepsch da Cunha, Nadia M. 1995. The Lecythidaceae of a central Amazonian moist forest. Mem. New York Bot. Gard. 75: 1-55.
Gustavia L.: [Article] Mori, S. A. 1987. The Lecythidaceae of a lowland Neotropical Forest: La Fumée mountain, French Guiana. Mem. New York Bot. Gard. 44: 1-190.
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Narratives