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Summary Venter, H. J. T. & Verhoeven, R. L.: A tribal classification of the Periplocoideae (Apocynaceae). – Taxon 46: 705‐720. 1997. – ISSN 0040‐0262. The diagnostic features used to delimit genera are enumerated and critically analysed. Floral characteristics are important: shape and depth of the corolla tube, and positions of outer corona, stamens, and gynostegium. Coronal structure is valuable but can be misleading. Vegetative features are sometimes consistent within genera and may serve as a complement to floral characteristics. The Periplocoideae are, for the first time, subdivided: three tribes are recognized, two of them newly described and named, and the individual genera and generic synonyms are mentioned for each. Some nomenclatural new combinations, required as a consequence of newly proposed synonyms, are validated in the genera Camptocarpus (4), Cryptolepis (4), Decalepis (2), and Pentopetia (2).

The development of the ovule and the embryo sac of five of the 17 species of Lycium and of one hybrid, recorded for southern Africa, was investigated. All specimens of four of the species and the hybrid (between a hermaphroditic and a functionally dioecious species) were found to be functionally dioecious: they express only one sex, although both male and female organs are present in the same tlower. One species was hermaphroditic. The embryo sacs of all species, and of the hybrid, were of the normal eight-nucleate Polygonum type. The structure of the ovary and the development of the embryo sac are similar to those of L europaeum L. The absence of unreduced embryo sacs indicates that apomixis does not occur at any ploidy level in the species studied.

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