392 MANUAL OF BOTANY 



latitudes. Illustrative Genera : — Convolvulus, Linn. ; Ipomoea, 

 Linn. ; Cuscuta, Linn. There are about 750 species. 



Properties and Uses. — They are chiefly remarkable for the 

 presence of an acrid milky purgative juice in their roots ; hence 

 the order includes some imj)ortant medicinal plants. In the 

 roots of some species this purgative principle is either absent or 

 in but small quantity. The seeds also of some species are 

 purgative. The Cuscuteae are leafless parasites. 



Order 197. Nolanace^, the Nolana Order. — C h a r a c t e r. — 

 Herbs or shrubs. Leaves alternate, exstipulate. Calyx 5-partite, 

 persistent, with a valvate aestivation. Corolla regular, with a 

 plaited aestivation. Stamens 5, opposite to the lobes of the calyx. 

 Ovary composed of from 5 to 20 carpels, either distinct or more 

 or less combined into several bundles ; style on a fleshy disc, 

 simple ; stigma simple. Fruit composed of 5 or more separate 

 or more or less combined achaenia, which are enclosed in the 

 persistent calyx. Seed with a little albumen ; embryo cui'ved ; 

 radicle inferior. This order is combined by Bentliam and 

 Hooker with Convolvulacecs ; and by others it has been referred 

 to Boraginacece. 



Distribution and Numbers. — Natives exclusively of South 

 America, especially of Chili. Illustrative Genera : — Nolana, 

 Linn. ; Alona, Lindl. There are about 36 species. 



Properties and Uses. — Unknown. 



Order 198. Solanace^, the Solanum Order. — C h a r a c t e r. — 

 Herbs, or rarely shrubs, or trees, with a colourless juice. Leaves 

 alternate, often in pairs. Inflorescence axillary, or frequently 

 extra- axillary. Floivers isomerous. Calyx with 5 or rarely 4 

 divisions, usuall.y persistent, often growing during the rij)ening 

 of the fruit {accrescent). CoroZZa regular or somewhat irregular, 

 5- or rarely 4-partite ; cestivation valvate, induplicate, plaited, or 

 imbricate. Stamens equal in number to the lobes of the corolla, 

 with which they are alternate ; anthers 2-celled, sometimes 

 connate above, with longitudinal or porous dehiscence. Ovary 

 superior, usually 2-celled, rarely 3— 5-celled; stijle undivided, 

 stigma simple or 2-lobed. Fruit capsular or baccate, 2- or more- 

 celled. Seeds numerous, albuminous ; emb7-yo straight, or usually 

 curved in a more or less annular or spiral form. 



Diagnosis. — Herbs or rarely shrubs or trees, with alternate 

 leaves, and a colourless juice. Flowers isomerous. Calyx and 

 corolla with 5, or rarely 4 divisions. Corolla regular or very 

 slightly irregular ; aestivation valvate, imbricate, plaited, or 

 induplicate. Stamens equal in number to the lobes of the 



