[family CHRYSOBALANACEAE]

Herbarium
Royal Botanic Gardens, Kew (K)
Collection
Flora Zambesiaca
Resource Type
Reference Sources
Entry From
FZ, Vol 4, Part 0, page 33, (1978) Author: F. White
Names
[family CHRYSOBALANACEAE]
Information
Trees, shrubs or rhizomatous, geoxylic suffrutices. Wood always with abundant silica inclusions. Leaves simple, entire, alternate, often coriaceous, usually with two glands at base of lamina or near apex of petiole. Stipules small and caducous to large and persistent. Inflorescence a cyme, panicle or raceme. Flowers mostly (in our area always) bisexual, actinomorphic to zygomorphic, strongly perigynous. Receptacle-tube short to elongate, straight or curved, often gibbous at the base, always lined with nectariferous tissue which is extended at the throat as a short annular disk; throat at least partly blocked by long hairs. Sepals 5, free, imbricate, often unequal, ascending or reflexed. Petals 5, rarely absent (not in our area), sometimes unequal, imbricate, often caducous. Stamens 2–100 or more, included or exserted, inserted in 1 or 2 rows on the margin of the disk or adnate to its abaxial surface, either all fertile and forming a complete circle or partly staminodial; filaments free or appearing connate at the base or (not in our area) ligulately connate; anthers small, 2-thecous, dehiscing longitudinally. Ovary superior, basically of 3 carpels and gynobasic but usually with only 1 carpel fully developed, attached to base, middle or mouth of receptacle-tube, sessile or on a short gynophore, always hairy, each carpel 1-locular with 2 ovules, or 2-locular, owing to a false septum, with 1 ovule in each compartment; style filiform; stigma distinctly or indistinctly 3-lobed. Fruit a dry or fleshy drupe; endocarp thick or thin, fibrous, granular or bony, often with a special mechanism for seedling escape, often densely hairy inside. Seed erect, exalbuminous; cotyledons plano-convex, fleshy, sometimes ruminate. Germination hypogeal or epigeal; first leaves of seedling opposite or alternate.
Range
A medium-sized family of 16 genera and 450 species distributed throughout the tropical regions of both hemispheres, but with the greatest concentration of genera in Africa and Madagascar, and of species in tropical America.
Notes
The Chrysobalanaceae was first recognized as a family by Robert Brown in 1818, and has been maintained as such by all subsequent workers with detailed knowledge of the group. In most general systems of classification, however, it appears as a tribe or subfamily of Rosaceae. Convincing evidence for its claim to family rank is summarized by Prance (Fl. Neotrop. 9, Chrysobalanaceae). Parinari, in its usual circumscription, is a highly artificial assemblage—a dumping ground for all species of Chrysobalanaceae with a 2-locular ovary. Prance has convincingly shown that it should be split into several, more natural, units. Of these, only Maranthes occurs in our area. The differences between Maranthes and Parinari sens. strict, are as great as those between any other pair of genera in the family. A striking feature of the African flora is the frequent occurrence of tree species, the distributions of which transgress important chorological boundaries and which also occur in markedly different vegetation types. No less remarkable is the frequent occurrence of pairs, or larger groups, of closely related species, the individual members of which are very different in their ecology and often also in their habit, but in other structural features are almost indistinguishable. These are the séries écophylétiques of Aubréville (Contribution à la paléohistoire des forêts de 1’Afrique tropicale, 1949). Examples of both kinds of relationship are well represented in the Chrysobalanaceae. Chrysobalanus icaco and Magnistipula butayei are ecological and chorological transgressors which show subspecific differentiation. Parinari excelsa is an ecological and chorological transgressor, which, in my opinion, does not show subspecific differentiation. The species of Hirtella, Maranthes and Parinari occurring in our area are all members of ecophyletic series. The structure of the leaves of an ecophyletic series in Parinari has been described by Homes, Duvigneaud, Balasse & Dewit (in Bull. Soc. Roy. Bot. Belg. 84: 83, 1951). Within F.Z. area those members of ecophyletic series that have sympatric distributions appear to behave as perfectly good biological species. Intermediates that may be of hybrid origin have either not been detected or are very localized and require confirmation (see p. 41). Since this account was written a paper by White on “The taxonomy, ecology and chorology of African Chrysobalanaceae (excluding Acioa)” has been published (Bull. Jard. Bot. Nat. Belg. 46: 265–350, 1976), as a companion to a series of distribution maps (Distr. Pl. Afr. 10: 281–334, 1976) of the African taxa, including all those mentioned in the Flora Zambesiaca account.
[family CHRYSOBALANACEAE]
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