500 BOTANY. 



the particulars as to Pinguicula, see Darwin's "Insectivorous Plants," 

 pp. 368-394, and for Utricularia, pp. 395-444.) 



Order Orobanchaceee. Lesifless parasitic herbs, numbering 150 

 species, widely distributed. We bave about a dozen native species in 

 the United States. 



Order Scrophulariacese. The Figwort Family. Herbs or shrubs, 

 rarely trees, with two-celled ovaries and central placentae. The 

 species, of which there are about 2000, are found in all parts of the 

 world, extending in both hemispheres to the limits of vegetation. 

 Many of the species contain an acrid poisonous principle. (Figs. 419-22.) 



Digitalis purpurea, the Foxglove, a small plant of Europe, affords 

 the drug Digitalis, which is officinal. 



Many species are cultivated for their fine flowers ; among these are 

 the Snapdragon (Antirrhinum), Monkey Flower (Mimulus), Mauran- 

 dia, Pentstemon, Veronica, Calceolaria, etc. , etc. 



Pauluwnia imperialis, a small tree of Japan, is planted in the 

 Southern States. 



Verbascum Thapsus, the Common Mullein, is a weed introduced from 

 Europe. 



582. Cohort XIV". Polemoniales. Plants with alter- 

 nate leaves, regular flowers, stamens isomerous Avith the 

 corolla lobes, and ovary superior. 



Order Solanacese. The Nightshade Family. Herbaceous or woody 

 plants with a watery juice ; ovary two-celled, many ovuled. This 

 large order of from 1200 to 1500 species, which are chiefly tropical, is 

 pervaded by a more or less poisonous principle. (Figs. 423-7.) 



There are, however, a few valuable food plants. 



Solanum tuberosum, the Potato, is a native of America from Mexico 

 to Chili, and a variety of it (var. boreale) even occurs in New Mexico. 

 The potato was introduced into Spain in the early part of the sixteenth 

 century, and into England by Sir Walter Raleigh in 1586, but for 

 nearly a century from the latter date it was little used. It is now, 

 however, grown extensively in nearly all countries. In its wild state 

 its tubers are not more than two to three centimetres in diameter, but 

 by culture and selection they have been increased fifteen to twenty 

 times in bulk. 



Solanum Melongena, the Egg Plant, of South America, is now grown 

 with us for its egg-shaped edible fruits. 



Lycopersicum enculentum, the Tomato, of South America, is grown 

 in most warm and temperate countries for its wholesome fruits. 



PJiysalis Alktkengi, the Winter Cherry or Strawberry Tomato, of 

 the South of Europe, is grown in our gardens for its edible fruit, which 

 is enclosed in the inflated calyx. Our native species of this genus, 

 called commonly Ground Cherries, are valuable for food. 



