418 MANUAL OF NATURAL HISTORY. 



shrubs, usually twining and milky ; leaves 

 alternate, undivided or lobed, exstipulate ; 

 inflorescence axillary or terminal ; calyx per- 

 sistent, in five divisions, imbricated ; corolla 

 deciduous, limb 5-lobed; aestivation plaited 

 or imbricated; stamens five, alternate with 

 segments of corolla; ovary simple, 2 4-celled ; 

 style one ; placentae basal ; fruit 1 4-celled, 

 succulent or capsular ; cotyledons leafy, 

 doubled up. Abundant in tropical, but rare 

 in cold climes. Roots generally afford an 

 acrid juice ; yield Jalap, Scammony, Sweet 

 Potato, Oil of Rhodium, c. 



4. FAMILY. Sebestens (Cordiaceae). Trees; leaves 



alternate, rough, exstipulate ; flowers pani- 

 cled, bracteate ; calyx 4-^5-toothed ; corolla 

 4-^5-clefb, imbricated ; stamens five, free ; 

 ovary 4-8-celled ; stigma 4-8-cleft ; fruit 

 drupaceous, 4-8-celled ; seeds exalbuminous ; 

 cotyledons leafy, plaited longitudinally. 

 Mostly tropical species in both worlds. 



5. FAMILY. Milk-Weeds (AsclepiadaeeaB). Shrubs, 



occasionally herbs, usually milky, often twin- 

 ing; leaves mostly opposite, with inter- 

 petiolary cilia in place of stipules ; flowers 

 umbelled, fascicled, or racemose ; calyx 5-di- 

 vided, persistent ; corolla 5-lobed, deciduous ; 

 aBstivation imbricate, rarely valvate; stamens 

 five ; anthers and stigma consolidated into a 

 column ; ovaries two; fruit, two follicles, one 

 sometimes abortive , seeds numerous ; coty- 



