520 USEFUL PLANTS AND PLANT PRODUCTS 



The rue family contains a rather small number of trees and 

 shrubs, with only two common genera, the prickly ash and the 

 hop tree in temperate North America, and comprises, among 

 others, the orange sub-family. Under this is found the genus 

 Citrus, which embraces all the citrous fruits. The species and 

 varieties which are found in our markets may be classed as 

 oranges, grape fruit, and lemons. 



Most of our oranges are now of American growth, coming 

 from California or Florida, and many of the very large fruited 

 species of Citrus from Polynesia, variously known as pomelo 

 and grape fruit, are raised in both these states, while some are 

 also imported from the West Indies. The best lemons are im- 

 ported from the Mediterranean coast, largely from Sicily. 



The grape family numbers about 300 species of climbing- 

 shrubs. Only the grape genus Vitis is a source of edible fruits, 

 - the berries so familiar as fresh grapes or raisins. 



Of these there are two principal types, one comprising the 

 European (Malaga and other) varieties with solid pulp, found 

 also in such California varieties as the Tokay grape, all of which 

 are descended from one European species. The other type is 

 the one with soft pulp, readily separated from the skin, such 

 as the Catawba, Delaware, Isabella, and Concord varieties. These 

 have to some extent been introduced into Europe, but are 

 descendants of native American species. Grapes are consider- 

 ably cultivated in most of the states, but nowhere else so exten- 

 sively as in California, where they are raised for wine making, for 

 the manufacture of raisins, and for shipment in a fresh condition. 



The heath family supplies berries of several species, such as 

 the familiar cranberries and the blueberries and huckleberries, 

 which are largely gathered for the market in several of the 

 northeastern states, particularly in Maine, and are somewhat 

 extensively canned. 



From the olive family (mostly sub-tropical trees and shrubs) 

 are obtained olives, which constitute a table delicacy, while 

 the oil is a highly valuable food. 



