354 



MANUAL OF BOTANY 



stigmas 3, sessile, 2-lobed. Fruit winged, capsular. Seeds 

 numerous, with a thin reticulated testa, and without albumen. 



Distribution and Nwmbers. — Natives chiefly of India, South 

 America, and the West Indies. Illustrative Genera : — Begonia, 

 Linn.; Diploclinium, imdL There are more than 160 species. 



Properties amd Uses. — They are generally reputed to possess 

 astringent and bitter properties, and occasionally to be purgative. 



Order 155. Datiscace^, the Datisca Order. — Character. — 

 Herbs, or in the case of Tetrameles a large tree. Leaves alter- 

 nate, exstipulate. Flowers diclinous, apetalous. Male flower 

 with a 3 — 4-cleft calyx. Stamens 8 — 7 ; anthers 2-celled, linear, 

 bursting longitudinally. Female flower with a superior 3 — 4- 



FiG. 1113. 



Fig. 1114. 



Fi(/. 1113. Vertical section of 

 tlie flower of the Prickly 

 Pear {Opuntia vulgaris). 



Fig. 1114. Diagram of 



the flower of the same. 



toothed calyx, and a 1-celled ovary, with 3 — 4 polyspermous 

 parietal placentas. Fruit dry, opening at the apex. Seeds 

 without albumen, minute, numerous. 



Distribution and Numbers. — They are widely distributed 

 over the globe. Illustrative Oenera : — Datisca, Linn. ; Tetra- 

 meles, B. Br. The above are the only genera : there are 4 

 species. 



Properties and Uses. — Of little importance. 



Cohort 4. — Ficoidales. 



Order 156. Cactace.s;, the Cactus Order. — Character. — 

 Succulent plants, which are usually spiny and leafless. Stems 

 fleshy, globular, columnar, flattened, or 3- or more-angled, and 



