Vanguerieae
Introduction '''Vanguerieae''' is a tribe of flowering plants in the family Rubiaceae and contains about 655 species in 30 genera. It is one of the most species-rich groups within the family and it is distributed across the Paleotropics.
Description Spines on ''Canthium angustifolium''Stylar head-complex of ''Vangueria dryadum''Several different life forms are present in the tribe: most species are shrubs, but geofructices (plants with woody rhizomes) (e.g. ''Fadogia homblei'', ''Pygmaeothamnus zeyheri''), small trees (e.g. ''Vangueria infausta''), and climbers (e.g. ''Keetia gueinzii'') also occur. As all Rubiaceae species, the leaves are opposite, simple and entire, and they have interpetiolar stipules. The phyllotaxis is decussate, sometimes conspicuously so (e.g. ''Canthium inerme''), and rarely whorled (e.g. ''Fadogia''). Some species have spines (e.g. ''Canthium''). Secondary pollen presentation is characteristic for the tribe and the species develop a conspicuous “stylar head”-complex, which is a structural unit consisting of a pollen presenting organ combined with stigmatic surfaces.
Distribution and habitat The species of this tribe are found in the Paleotropics. Most genera and over 70% of the species occur in Sub-Saharan Africa, including Madagascar and the islands in the Western Indian Ocean. The remainder of the species is mostly found in Southeast Asia. A few species are restricted to islands in the Pacific Ocean, especially New Caledonia, and another fraction of the species occurs in the Eastern states of Australia, especially in coastal Queensland. The countries with the largest diversity with over a hundred species each are Tanzania, Madagascar and D.R.Congo.The tribe is characterized by a high degree of endemism. Several monotypic genera have a restricted distribution range: ''Eriosemopsis'' is found in the KwaZulu-Natal province of South Africa, ''Everistia'' occurs in the Eastern states of Australia, ''Perakanthus'' occurs in Peninsular Malaysia, and ''Temnocalyx'' is only found in southwestern Tanzania. Other larger genera with a restricted range are ''Cyclophyllum'' that is mainly found in New Caledonia, ''Peponidium'' that is only found on Madagascar or the Comoros, and ''Pyrostria'' of which most species are restricted to Madagascar.The tribe is a common and important constituent of many different kinds of habitats. Species of Vanguerieae are found in both extreme wet habitats, such as the rainforests of tropical Africa, and in the very dry desert-like areas of the horn of Africa and of the southernmost part of Madagascar. The tribe is found at elevations of over  in the mountains of Malawi and Tanzania, but also at sea-level along the coast of South Africa.
Ecology There is a wide range of flower sizes and fruit morphologies, suggesting different adaptations to pollination and dispersal. Most of the species are probably pollinated by insects, but it is suspected that at least some of the large-flowered species of ''Fadogia'' are bird-pollinated. The edibility of many fruits suggests that they are dispersed by animals.Almost 30% of the species within the tribe have a symbiosis with endophytic bacteria, which are found intercellularly within the leaves. The presence of these bacteria is consistent on a genus level and all species belong to the following 5 genera: ''Fadogia'', ''Fadogiella'', ''Globulostylis'', ''Rytigynia'', and ''Vangueria''. The bacteria are identified as ''Burkholderia'', which is a genus that is also found in the leaves of other Rubiaceae species. The hypothesis is that these endophytic bacteria provide chemical protection against insect herbivory.
Uses  Ripe fruit of ''Vangueria infausta''Some species are consumed locally and fruits may be used as famine food. Examples are African medlar (''Vangueria infausta'') and Spanish tamarind (''Vangueria madagascariensis''), but the fruits of other ''Vangueria'' and ''Fadogia'' species are edible too.In West Africa, ''Vangueria agrestis'' (known under its old name ''Fadogia agrestis'') is traditionally used as an aphrodisiac. It is known as ''bakin gagai'' (Hausa) or black aphrodisiac.
Systematics ===Taxonomy===The first genus of the tribe to be described was ''Canthium'', containing the species ''C. coronatum'' (now ''Catunaregam spinosa'' in the Gardenieae tribe) and ''C. parviflorum'' (now ''C. coromandelicum''). The second genus to be described was ''Psydrax'', containing the species ''Psydrax dicoccos''. Although the tribe is predominantly found in Africa, these first described species are Asiatic taxa. The first non-Asiatic taxa to be described were the genera ''Pyrostria'' and ''Vangueria'', based on material collected on Western Indian Ocean islands. The first genus from continental Africa was ''Cuviera'', with the species ''Cuviera acutiflora'' from Sierra Leone. Dumortier first mentioned a tribe Vanguerieae (as “Vaugnerieae”) attributed to Achille Richard and put the genera ''Hamelia'', ''Evosmia'', ''Mitchella'', ''“Vaugneria”'' (''Vangueria''), and ''Nonatelia'' in it. However, this circumscription of the tribe was far from correct, as ''Canthium'' and ''Cuviera'' were put in different tribes and ''Psydrax'' and ''Pyrostria'' were not even mentioned. Also, the only genus that actually belongs in the tribe is ''Vangueria''; the other genera belong elsewhere. At that time, authors often used the number of locules as a character for delimiting groups, but this is problematic for Vanguerieae as both 2-locular (e.g. ''Canthium'') and 5-locular (e.g. ''Vangueria'') ovaries occur in the tribe. The first monograph of the tribe was performed by Walter Robyns in 1928 and a total of 17 genera were allocated to the tribe. Although 9 new genera were described, this work was not entirely complete, e.g. ''Canthium'', ''Cuviera'', and ''Pyrostria'' were not treated. Since then, several new genera have been described or made synonym and more taxonomic adjustments on genus level will probably still be necessary.===Genera===Currently accepted names* ''Afrocanthium'' (Bridson) Lantz & B.Bremer (17 sp)* ''Bridsonia'' Verstraete & A.E.van Wyk (1 sp)* ''Bullockia'' (Bridson) Razafim., Lantz & B.Bremer (6 sp)* ''Canthium'' Lam. (81 sp)* ''Canthiumera'' K.M.Wong & Mahyuni (4 sp)* ''Cuviera'' DC. (10+6 sp)* ''Cyclophyllum'' Hook.f. (44 sp)* ''Dibridsonia'' K.M.Wong (3 sp)* ''Eriosemopsis'' Robyns (1 sp)* ''Everistia'' S.T.Reynolds & R.J.F.Hend. (1 sp)* ''Fadogia'' Schweinf. (40 sp)* ''Fadogiella'' Robyns (3 sp)* ''Globulostylis'' Wernham (8 sp)* ''Hutchinsonia'' Robyns (2 sp)* ''Kanapia'' Arriola & Alejandro (2 sp)* ''Keetia'' E.Philipps (36 sp)* ''Meyna'' Roxb. ex Link (9 sp)* ''Multidentia'' Gilli (10 sp)* ''Peponidium'' (Baill.) Arènes (48 sp)* ''Perakanthus'' Robyns ex Ridl. (1 sp)* ''Plectroniella'' Robyns (1 sp)* ''Psydrax'' Gaertn. (90 sp)* ''Pygmaeothamnus'' Robyns (1 sp)* ''Pyrostria'' Comm. ex A.Juss. (67 sp)* ''Robynsia'' Hutch. (1 sp)* ''Rytigynia'' Blume (82 sp)* ''Temnocalyx'' Robyns (1 sp)* ''Vangueria'' Juss. (58 sp)* ''Vangueriella'' Verdc. (18 sp)* ''Vangueriopsis'' Robyns (4 sp)Synonyms* ''Ancylanthos'' Desf. = ''Vangueria''* ''Clusiophyllea'' Baill. = ''Canthium''* ''Dinocanthium'' Bremek. = ''Pyrostria''* ''Dondisia'' DC. = ''Canthium''* ''Lagynias'' E.Mey. ex Robyns = ''Vangueria''* ''Leroya'' Cavaco = ''Pyrostria''* ''Lycioserissa'' Roem. & Schult. = ''Canthium''* ''Mesoptera'' Hook.f. = ''Psydrax''* ''Mitrastigma'' Harv. = ''Psydrax''* ''Neoleroya'' Cavaco = ''Pyrostria''* ''Pachystigma'' Hochst. = ''Vangueria''* ''Phallaria'' Schumach. & Thonn. = ''Psydrax''* ''Plectronia'' Lour. = ''Canthium'', ''Peponidium'', ''Psydrax''* ''Pseudopeponidium'' Homolle ex Arènes = ''Pyrostria''* ''Psilostoma'' Klotzsch ex Eckl. & Zeyh. = ''Canthium''* ''Rhopalobrachium'' Schltr. & K.Krause = ''Cyclophyllum''* ''Scyphochlamys'' Balf.f. = ''Pyrostria''* ''Tapiphyllum'' Robyns = ''Vangueria''* ''Vavanga'' Rohr = ''Vangueria''===Phylogenetic relationships===The following phylogenetic tree is based on molecular phylogenetic studies of DNA sequences.
Image gallery File:Canthium angustifolium Roxb. 7.JPG|''Canthium angustifolium''File:Canthium coromandelicum in Keesaraguda, AP W IMG 9056.jpg|''Canthium coromandelicum''File:Cyclophyllum coprosmoides flowers and foliage.jpg|''Cyclophyllum coprosmoides''File:Everistia vacciniifolia var. vacciniifolia flowers.jpg|''Everistia vacciniifolia''File:Fadogia homblei01.jpg|''Fadogia homblei''File:False Turkeyberry (Canthium armatum) (16462475912).jpg|''Plectroniella armata''File:Psydrax banksii (8467185479).jpg|''Psydrax banksii''File:Psydrax foliage.jpg|''Psydrax latifolia''File:Psydrax livida, bloeiwyses, b, Seringveld.jpg|''Psydrax livida''File:Psydrax odorata (5816464018).jpg|''Psydrax odorata''File:Vangueria infausta, habitus, a, Pretoria NBT.jpg|''Vangueria infausta''File:Vangueria infausta, blomme, Schanskop, b.jpg|''Vangueria infausta''File:Vangueria infausta, groen vrugte, Faerie Glen NR.jpg|''Vangueria infausta''File:Vangueria parvifolia, vrug, Walter Sisulu NBT.jpg|''Vangueria parvifolia''File:Vangueria macrocalyx, b, Skeerpoort.jpg|''Vangueria macrocalyx''
References