The Scrophulariaceae in the flora of Central Africa (excl. Lindernieae).
The family Scrophulariaceae (trees, shrubs and herbs) in Central Africa, an area defined here as including Zaire, Rwanda and Burundi, and covering an area of 2 399 697 km2, consists of 42 genera and 186 species, divided into 3 subfamilies, the Scrophularioideae, the Rhinanthoideae and the Orobanchoideae. The type subfamily comprises 8 tribes, Verbasceae, Aptosimeae, Cheloneae, Gratioleae, Lindernieae, Hemimerideae, Selagineae and Antirrhineae with 24 genera and 84 species. Of these, only the Lindernieae had been already fully revised for the whole of tropical Africa. The subfamily Rhinanthoideae comprises 3 tribes with 17 genera and 100 species. Finally the remaining subfamily of the Orobanchoideae comprises a single tribe with a single genus and a single species, only. This paper is a taxonomic revision of all the tribes excluding the Lindernieae. A total of 37 genera and 139 species, some of them with infraspecific taxa including subspecies and varieties are recognized. All taxa are fully described and drawings for 74 species are given. In addition, keys to subfamilies, tribes, genera, species, subspecies and varieties, as well as ecological and phytogeographic data are provided to assist in the correct identification of the taxa. Buchnera bampsiana, B. dilungensis, B. libenii, B. philcoxii, B. robynsii, B. symoensiana, B. vandenberghenii and Harveya wysockiana are described as new species. Furthermore, 3 new combinations, Sopubia conferta var. congensis, S. mannii var. metallorum and S. parviflora subsp. eminii are made. In addition, 9 new sections and 4 subsections are described. The most frequent occurrence of the Central African Scrophulariaceae is in the submontane and lower montane zone, generally between 600 and 2200 m altitude. They are mostly associated with open formations of savannas, especially steppe savannas in the high plateaux, as well as woodlands. From the equatorial forest only 2 species are reported, Harveya thonneri and Striga hallaei. The overwhelming majority of the Central African Scrophulariaceae is concentrated in Haut-Katanga (98 species, including 25 probably endemic) and Burundi (51 species).