210. PEDALIACEAE 499 



6. Ovules 2 in each cell of the ovary 7 



Ovules 8 or more in each cell of the ovary. Anthers opening by long slits. 



Disc one-sided. Succulent, prostrate herbs 9 



7. Fruit 4-winged, without spines. Anther-halves divergent, opening by 



short slits. Disc one-sided. Corolla yellow or red. Stem tuberous 

 at the base. — Species 15. Central and South Africa. 



Pterodiscus Hook. 



Fruit wingless, bearing spines or tubercles. Corolla yellow. Succulent 



herbs 8 



8. Fruit with a large spine at the base of each angle. — Species i. East 



Africa and Madagascar. Yields vegetables and is used in medicine. 



Pedalium Royen 



Fruit without large spines at the base, but with small spines or tubercles 



on the flanks. Seeds winged. — Species i. East Africa. (Under 



Pedalium Royen) Pedaliophytum Engl. 



9. Ovules 8 in each cell of the ovary. Corolla yellow ; tube deeply saccate 



at the base. — Species i. South-east Africa. . Holubia Oliv. 

 Ovules numerous in each cell of the ovary. Corolla red ; tube not or slightly 

 saccate at the base. Fruit with several rows of recurved spines. — 

 Species 3. South and Central Africa. Noxious weeds. " Grapple 

 plant." {Uncaria Burch.) Harpagophytum DC. 



10. 0^•ules 2 — 3 in each chamber of the ovary, ascending, or one ascending, 



the other descending. Fruit a nut 11 



Ovules numerous in each chamber, at least in the larger ones, descending or 

 horizontal. Fruit a capsule 12 



11. Ovules 2 in each of the 4 chambers of the ovary. Fruit with 2 spines 



in the middle. Corolla red. Trailing herbs. Leaves lobed. — Species i. 



Tropical and South Africa Pretrea J. Gay 



Ovules 3 in each chamber Shrubs. — Species i. Northern East Africa 

 (Somaliland) Pretreothamnus Engl. 



12. Cells of the ovary and fruit unequal in size and containing an unequal 



number of ovules or seeds. Corolla violet or white. Fruit with 2 — 8 

 spines or tubercles at the base ; only the larger cell dehiscent. Erect 

 herbs. Leaves toothed or lobed. Flowers usually in cymes. — Species 



3. Central Africa to Namaland Rogeria J. Gay 



Cells of the ovary and fruit equal. Flowers solitary 13 



13. Fruit with two horns or spines at the apex. Corolla red, violet, or yellow. — 



Species 5. Central and South Africa. Some are used as ornamental or 



medicinal plants Ceratotheca Endl. 



Fruit without horns nor spines. Corolla red or white. — Species 20. 

 Central and South Africa ; one species (S. indicum L.) also cultivated in 

 Egypt and Madagascar. The seeds of this and a second species are used 

 as food or as a condiment and for preparing meal and oil ; some species 

 5äeld dyes or medicaments or serve äs ornamental plants. (Plate 138.) 



Sesamum L. 



