660 A TEXT-BOOK OF BOTANY. 



gency of the unripe fruit is due to the tannin which it contains. 

 When it is ripe, which is not until after the appearance of frost, 

 it is palatable and contains considerable malic acid and sugars. 

 The Japanese persimmon is a cultivated variety of D. Kaki and 

 produces a large orange-colored fruit which is not uncommon in 

 the fruit markets in many parts of the world. At the present 

 time the plant is cultivated in California. 



The bark of our native persimmon is used in medicine. It 

 contains considerable tannin which resembles gallotannic acid, and 

 a crystalline resinous principle with a peculiar odor and slightly 

 astringent taste. 



c. STYRACACE^: OR STORAX FAMILY. The flowers 

 of this family somewhat resemble those of the Ebenaceae, but the 

 filaments of the stamens are united in a single series, and there 

 is a single slender style. 



Styrax Benzoin is a medium-sized tree with long, ovate, acu- 

 minate leaves which are very hairy on the under surface. The 

 flowers occur in terminal racemes, and are silvery white on the 

 outer surface and reddish-brown on the inner surface. The bal- 

 samic resin yielded by this plant is official as benzoin. 



IV. ORDER GENTIANALES OR CONTORTS. 



The plants of this order have opposite leaves, the flowers are 

 regular and the gynaecium consists of two separate carpels. The 

 order includes five families, all of which furnish medicinal plants. 



a. OLEACEyE OR OLIVE FAMILY. This family is 

 chiefly of interest because of the olive and manna trees. 



The olive tree (Olea europcea} is indigenous to the Orient and 

 is now cultivated extensively in Southern Europe, Northern 

 Africa, the islands of the Mediterranean, tropical America, includ- 

 ing the Southern United States, and in California. The leaves 

 are narrow-lanceolate, entire, coriaceous and evergreen. The 

 flowers are small, white, diandrous and in axillary racemes. The 

 fruit is a drupe, the sarcocarp of which is rich in a fixed oil 

 known as olive oil. The oil is obtained by expression, and is 

 official. Depending upon the character of the fruits and the 

 amount of oil which they yield, over forty varieties are recognized. 



