The putative complexity of Combretaceae and lack of information on phylogenetic relationships within the family led us to explore relationships between genera of Combretaceae by means of combined analyses of plastid and nuclear sequences. We collected DNA sequence data from the nuclear ribosomal internal transcribed spacer region and plastid rbcL, psaA-ycf3 spacer and psbA-trnH spacer for 14 of the 17 genera of Combretaceae. The current classification of the family into two subfamilies, Strephonematoideae and Combretoideae, is corroborated. Within Combretoideae, division into two tribes, Laguncularieae and Combreteae, is strongly supported. Within Combreteae subtribe Terminaliinae, relationships between genera are largely unresolved. Terminalia is not supported as monophyletic and two groups were identified, one containing mainly African species and another of mostly Asian species. Pteleopsis, Buchenavia and Anogeissus are embedded within Terminalia, and we suggest that all genera of Terminaliinae, with the exception of Conocarpus, should be included in an expanded circumscrition of Terminalia. Within subtribe Combretinae, a clade formed by the two monotypic genera Guiera and Calycopteris is sister to the rest of the subtribe. Groupings in Combretinae are consistent with recent results based on morphological data. Combretum is currently divided into three subgenera: Apethalanthum, Cacoucia and Combretum. The last two were included in this study and supported as monophyletic if Quisqualis is included within subgenus Cacoucia. Meiostemon is sister to subgenus Combretum. We recommend that subgenus Combretum should be expanded to include Meiostemon and subgenus Cacoucia to include Quisqualis. The sectional classification within Combretum proposed in earlier morphological studies is confirmed except for the exclusion of C. imberbe from section Hypocrateropsis in a separate and monotypic section and the inclusion of C. zeyheri (section Spathulipetala) in section Macrostigmatea. In order to accommodate C. imberbe, a new section is suggested. The reinstatement of previously recognized sections Grandiflora and Trichopetala, both of which had been sunk into subgenus Cacoucia section Poivrea, is proposed.

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Gymnosporia (Wight & Arn.) Hook. f. (Celastraceae) is an Old World genus of about 99 species and 19 infraspecific taxa. A historical review of the genus and its conserved status are given. Sectional subdivision of Gymnosporia into eight sections is based mainly on characters from fruit morphology and leaf anatomy. Taxonomically useful characters at section level include: presence or absence of leaf and fruit indumentum, number of valves in the fruit, aril colour and the degree to which it covers the seed. Diagnostic leaf anatomical characters are epidermis cell size, presence or absence of a hypodermis, uni–or multi–seriate epidermis, dorsiventral or isobilateral mesophyll and presence or absence of trichomes or papillae. The newly described sections (species/infraspecific taxa in brackets) are Buxifoliae (29); Capitatae (1); Gymnosporia (6/3); Mossambicenses (11/4); Vaccinifoliae (1/2); Pubescentes (1); Putterlickioides (1/2) and Tenuispinae (49/8). A key to the sections and a list of species in each section are provided. Morphological as well as leaf anatomical characters to assist in the identification of sections are tabulated. Eleven new name combinations, three new ranks and two new names are proposed.

The taxonomic status of Quisqualis L ., a genus closely related to and sometimes considered congeneric with Combretum Loefl ., is discussed . The genus Quisqualis is maintained to accommodate selected African, Indian, Asian and Malesian species (including Q. indica L . and Q. parviflora Sond .) . Diagnostic characters for Quisqualis include: leaves with abundant subepidermal crystalliferous idioblasts, each containing a large druse of calcium oxalate; leaves, stems and flowers with stalked glands but no scales; persistent petiole bases that develop into curved spines; petals well developed; hypanthium tubular or cylindrical, usually longer than 20 mm; stamens and style not or scarcely exserted; style adnate to hypanthium for more than half its length . Quisqualis shares a number of morphological similarities with Combretum Loefl . subgen . Cacoucia (Aubl .) Exell & Stace sect . Poivrea (Comm . ex DC .) G .Don . Some species of Combretaceae from West, West Central and East Africa have the style adnate to the upper hypanthium and display features reminiscent of both Quisqualis and Combretum. These species also have characters of their own and in the past were placed in different sections under Combretum . It is suggested that at least some of these species may be best classified in genera distinct from Combretum and Quisqualis, one of which is Campylogyne Hemsley . Combretum s.str. is defined on the basis of a combination of characters and includes species of which the upper hypanthium is variable in shape, but when tubular or cylindrical, then always shorter than 20 mm . Other diagnostic characters include: stamens exserted well beyond petals; style exserted and free, but when shortly adnate to upper hypanthium (only at the base or for a short distance), then stamens long-exserted . It is suggested that different pollination strategies have developed independently in the Combretum-Quisqualis clade, resulting in convergent morphological trends in floral morphology . These homoplasious similarities in floral morphology are at the root of the difficulties experienced to demarcate genera . An alternative classification is provided for those preferring to include the southern African Quisqualis parviflora under Combretum s. l. For this purpose, a new combination and name, Combretum sylvicola O.Maurin is provided . Quisqualis parviflora is confined to the Eastern Cape and KwaZulu-Natal coastal regions and does not extend beyond this area as has been claimed by some . A comparative table to differentiate among four groups in Quisqualis and Combretum in Africa, as well as a photo of a herbarium specimen and a distribution map of Quisqualis parviflora, are provided .