EXOGENS. 147 



The CONVOLVULACE^E, or Bind-weed family, are twin- 

 ing plants with showy flowers, except the tribe of Dod- 

 ders, (Cuscutecz,) which are leafless parasites. Here we 

 find the Jalap, and Scammony, and Sweet-Potato, (Bata- 

 tas, edulis^) 



The Nightshade family (SoLANACE^) contains the 

 Potato, (Solanum tuberosum^) the Deadly Nightshade, 

 (Atropa Belladonna^ the Henbane, (Hyoscyamus niger} 

 the Thorn-apple, (Datura Stramonium^) Tobacco, (Nice- 

 tiana Tabacum^) Cayenne-pepper, (Capsicum annium,} the 

 Tomato, (Lycopersicum esculentum^) etc. 



The LABIATE are characterized by two long and two 

 short stamens, four little nuts or naked seeds, and ir- 

 regular corollas. The plants are generally fragrant and 

 aromatic, and none of them are injurious. Many are 

 used in medicine as carminatives. Mint, Lavender, 

 Sage, Savory, and Balm, are examples of the family. 

 From Thyme a sort of camphor has been procured called 

 Thymol, which has similar antiseptic properties to Car- 

 bolic acid, but with pleasant odor. 



The family COMPOSITE is a very extensive one. The 

 florets are arranged in involucrated heads, and the an- 

 thers cohere into a cylinder. It is subdivided into three 

 sections: I. Cynarocephalce, (from cynara, the Artichoke,) 

 having all the flowers tubular; the involucre, hard, con- 

 ical, and often spiny, as the Thistle, Burdock, etc. 

 2. Corymbiferce, (corymbus, a comb, and fero, to bear,) 

 having tubular florets in the disk (center) and ligulate in 

 circumference, (or ray;) involucre hemispherical, leafy, or 

 scaly, rarely spiny, as Feverfew, Wormwood, Tansy, Ar- 

 nica, and Sunflower. 3. Cichoracece, (cichorium, succory,/ 



