502 BOTANY. 



Atropa Belladonna, the Deadly Nightshade, Hyoscyamus niger, 

 Henbane, and Datura Stramonium, the Thorn Apple, all of the Old 

 World, supply powerful narcotic medicines. That from the first, un- 

 der the name of Belladonna, is much used by oculists to dilate the pu- 

 pil of the eye. 



Nicotiana Tdbacum, Tobacco, a South American herb, was cultivated 

 by the American aborigines long before the advent of Europeans. It 

 was taken to Spain about the beginning of the sixteenth century, and 

 to England from sixty to eighty years later. It is now extensively 

 cultivated in many countries, especially in the United States, and is 

 used by all the civilized nations of the globe. Two or three other 

 species are also cultivated in different parts of the world. 



Among the ornamental plants of the order are species of Oestrum and 

 Datura, from South America and Mexico ; Lydum, from Europe ; 

 Petunia, from South America, etc., etc. 



The Thorn Apple mentioned above, and the Black Nightshade (So- 

 lanum nigrum) are common as weeds. The little black berries of the 

 latter are made into pi< j s and other pastry in the Mississippi Valley. 



Order Convolvulacese. Herbaceous climbers, rarely shrubs, often, 

 with a milky juice; ovary of 1-5 cells, ench 2-, rarely 1-4, ovuled. 

 About 800 species are known, distributed mostly in tropical and warm 

 temperate regions. They generally post-ess m acrid principle. 



The Common Morning-Glory (Iponwen pnrpurea) and one or two near 

 relatives, all from tropical America, are familiar ornamental climbers. 



Ipomoea Batatas, the Sweet Potato of India, has long been cultivated 

 in many warm and temperate climates for its nutritious roots. 



The purgative drug Jalap is derived from the root of a Mexican 

 plant Ipomoea purga. 



Convolvulus Scammonia, of Western Asia, yields the drug Scammony, 

 and from the wood of C. Scoparius, a shrubby species of the Canary 

 Islands, Oil of Rhodium is extracted. 



Cuscuta, the parasitic Dodder, includes many species. 



Order Borraginacese. The Borage Family. Usually hispid herbs, 

 shrubs, or trees, with a four-parted ovary, each part one-ovuled. The 

 1200 species are distributed throughout the world, although they are 

 most numerous in Southern Europe and Western and Central Asia. 

 Many of the species possess a mucilaginous property useful in making 

 cooling drinks, and the roots of some contain purple or brown dyes. 



Anchusa tinctoria, of the South of Europe, is grown in France and 

 Germany for its roots, which yield the red dye called Alkanet. 



Among the commonly cultivated ornamental plants may be men- 

 tioned the Forget-me-not (Myosotis palmtris) of Europe and the Helio- 

 trope (Heliotropium Perumanum) of Peru. There are several native 

 and introduced species which are vile weeds. 



Order Hydrophyllaceee. A small order of mostly American herbs, 

 closely related to the preceding. 



