Flowers short-stalked. 23 21. Calyx saucer-shaped, cleft to the middle. Petals free. Disc cupular, thick. Fruit large, elliptical, 1-celled. Seeds winged, with a long funicle. Trees. Leaves with 1-2 pairs of pinnae. Spikes panicled.--Species 1. Equatorial West Africa. Yields timber. =Fillaeopsis= Harms Calyx bell-shaped, shortly toothed. Disc inconspicuous or wanting. 22 22. Petals obviously united below. Fruit 1-celled, opening in two valves.--Species 13. Tropics to Delagoa Bay. Some species yield ebony-like wood. =Piptadenia= Benth. Petals free or nearly so. Fruit with thick, persistent sutures, the valves splitting transversely into one-seeded joints. Endocarp separating from the exocarp and persisting round the seeds. Shrubs.--Species 10. Tropical and South Africa. Some species (especially _E. scandens_ L. with fruits attaining a yard in length) yield soap-bark, fibre, vegetables, fish-poison, and edible oily seeds which are also used in medicine and as ornaments. (_Gigalobium_ P.Br., _Pusaetha_ L.) =Entada= Adans. 23. Disc cupular, thin. Ovary stalked. Seeds winged. Trees. Leaves with one pair of pinnae. Flowers with a very short stalk.--Species 1. Equatorial West Africa. Yields timber. (Including _Cyrtoxiphus_ Harms) =Cylicodiscus= Harms Disc inconspicuous or wanting. Ovary sessile or nearly so. Shrubs. Leaves with 3-12 pairs of pinnae. 24 24. Calyx-teeth more or less unequal. Buds oblique. Fruit woody, transversely septate, opening in two valves. Leaves with 3-6 pairs of pinnae.--Species 1. German East Africa. =Pseudoprosopis= Harms Calyx-teeth equal. Fruit leathery, with persistent sutures, the endocarp separating from the exocarp. Leaves with 6-12 pairs of pinnae.--Species 5. South Africa and southern Central Africa. They yield fish-poison and are used in medicine. =Elephantorrhiza= Benth. 25. (4.) Filaments free or the inner united into a ring. Petals white or yellow.--Species 80. They yield timber, fibre, soap-bark, gum (especially from _A. Senegal_ Willd., Verek), tanning and dyeing materials, perfumes, oil, and medicaments; some are used as ornamental plants. (Including _Vachellia_ Arn.) [Tribe ACACIEAE.] =Acacia= Willd. Filaments united into a tube, at least at the base. Petals white or red. Flowers in heads. Unarmed plants. [Tribe INGEAE.] 26 26. Fruit strongly curved or coiled, thick, leathery, separating into one-seeded joints or indehiscent. Petals united beyond the middle. Trees.--Species 3. Tropics; one species naturalized. They yield timber, gum, tanning and dyeing materials, edible fruits, and medicaments. =Pithecolobium= Mart. Fruit straight or nearly so. 27 27. Fruit dehiscing elastically. Petals united to the middle. Shrubs.--Species 5. Tropics. They yield timber, gum, and medicaments, and are used also as ornamental plants. =Calliandra= Benth.