4. Involucre of the partial inflorescences split at one side and consisting of 4 or more bracts. Ovary 3-celled. Style 3-or 6-cleft. Trees.--Species 3. Tropics. Poisonous and used medicinally. =Anthostema= Juss. Involucre closed all round and consisting of 4 bracts. Ovary 4-celled. Style 4-parted.--Species 3. Equatorial West Africa. =Dichostemma= Pierre 5. Involucre of the partial inflorescences with unequal lobes and with an appendage, in the axil of which the glands are inserted. Shrubs.--Species 2. Madagascar. =Pedilanthus= Neck. Involucre with equal lobes, but sometimes surrounded by a one-sided gland. 6 6. Involucre irregular, with a single gland sometimes embracing the partial inflorescence and split at one side only. 7 Involucre regular, with several glands sometimes united into a ring or cup. 9 7. Involucre with a narrow gland not enveloping the partial inflorescence. Female flowers with a perianth. Bracts subtending the involucres united high up. Spiny shrubs.--Species 1. East Africa. =Stenadenium= Pax Involucre with a broad gland enveloping the partial inflorescence. Herbs. 8 8. Female flowers with a perianth. Bracts subtending the involucres united at the base.--Species 2. East Africa. (Under _Monadenium_ Pax). =Lortia= Rendle Female flowers without a perianth. Bracts subtending the involucres united high up.--Species 10. Central Africa. =Monadenium= Pax 9. Glands of the involucre united into a ring or cup.--Species 10. Tropical and South-east Africa. Some are poisonous. =Synadenium= Boiss. Glands of the involucre separate. 10 10. Fruit a drupe.--Species 1. West Africa. (Under _Euphorbia_ L.) =Elaeophorbia= Stapf Fruit a capsule.--Species 320. Many of them are poisonous, some yield timber, gum, rubber, oil, and medicaments, or serve as garden-or hedge-plants. “Spurge.” =Euphorbia= L. 11. (2.) Filaments bent inwards in the bud. Calyx 4-6-partite, imbricate or subvalvate in bud. Corolla present, at least in the male flowers. Inflorescence spike-or raceme-like. Leaves and young shoots clothed with scales or stellate hairs.--Species 100. Tropical and South Africa. Several species are poisonous, some yield gum-lac, incense-wood, oil, and medicaments, or serve as ornamental plants. [Tribe CROTONEAE.] =Croton= L. Filaments straight in the bud. 12 12. Calyx of the male flowers with valvate or closed aestivation. [Especially tribe ACALYPHEAE.] 13 Calyx of the male flowers with imbricate or open aestivation. 59 13. Corolla present in the male flowers. 14 Corolla absent in the male flowers. 24 14. Petals of the male flowers more or less united. Rudimentary pistil cup-shaped or wanting. Style-branches 2. Flowers dioecious. Hairy undershrubs, shrubs, or trees. 15 Petals of the male flowers free from each other, but sometimes (_Caperonia_) adnate to the staminal tube; in this case rudimentary pistil club-shaped and style with many branches. 17