EXOGEN.E COROLLIFLOR^!. 



Stamens 5, unequal, on the tube of the corolla. Ovary 3- 

 celled ; stigma 3-lobed. Capsule 3-celled ; 3-valved, the 

 valves separating from the axis. Embryo in horny albumen. 



USES. Unknown . 



TYPICAL GENERA. Polemonium, Phlox, Gilia. 



Ill . GonvolvulacetK, Herbaceous plants, or shrubs, usually 

 twining and milky. Leaves alternate. Calyx permanent, in- 

 ferior, in 5 divisions, remarkably imbricated, often unequal. 

 Corolla hypogynous, plaited. Stamens 5, inserted towards 

 the base of the corolla. Ovary with 2 to 4 cells, few seeded ; 

 ovules erect ; style 1. Disk annular. Capsule with the 

 valves fitting at their edges to the angles of a loose dissepi- 

 ment. Seeds with mucilaginous albumen ; embryo curved ; 

 cotyledons shrivelled. 



USES. The roots of Convolvulus Scammonia yield Scam- 

 mony ; of Exogonium Purga, true Jalap ; of Ipomoea Bata- 

 toides, a kind of false Jalap, called Purga Macho ; and a great 

 many more possess similar properties. The Batatas, or Sweet 

 Potatoe, has the purgative quality so much diffused as to be a 

 valuable article of food ; the great roots of others have also 

 been found eatable. 



TYPICAL GENERA. Ipomoea, Convolvulus, Calystegia. 



Ipomoea Batatoides. 1. The pistil and annular disk. 2. A transverse section of 

 the ovary. 3. A capsule of Convolvulus tricolor. 4. A vertical section of the 

 seed of that species. 



