i8oo A TEXTBOOK OF THEORETICAL BOTANY 



toxicodendron is a climbing plant which clings in a way similar to Ivy and is 

 spoken of as Poison-ivy. It is common in North America and is notorious 

 for producing an acute dermatitis if touched. R. vernicifera is a native of 

 Japan. It is a small tree which yields lacquer which is obtained by notching 

 the trunk. R. succedanea, also native of Japan, is spoken of as the Wax Tree, 

 because the crushed berries yield a yellow wax. R. typhina is the Sumach, 

 a magnificent tree which is common in North America and is now widely 

 cultivated. 



The genus Anacardiiim contains eight species, of which A. occidentale 

 is the most important. It is largely cultivated as the Cashew Nut. The 

 flowers are polygamous and the ovary consists of a single carpel which 

 produces a kidney-shaped nut (Fig. 1693), with a hard acrid coat. The 



Fig. 1693. — Anacardiiim occidentale. 

 Cashew Nut. Fruit borne upon the 

 large, fleshy receptacle. 



receptacle below the gynoecium swells up into a pear-shaped structure 

 which is fleshy and edible. The stem yields a gum. The plant is a native of 

 tropical America. 



Even more important and better known is Mangifera indica (Fig. 1694), 

 the Mango, which is cultivated in most parts of the tropics. In fact records 

 indicate that it has been known for its fruits for as far back as 5,000 or 

 6,000 years. The tree is a large one, up to 70 ft. in height, and as much as 

 5 ft. thick. It grows very rapidly and endures any amount of pruning. 

 These prunings are often used not only for firewood but also for charcoal. 

 The solitary carpel develops into a drupe with a fibreless mesocarp which 

 contains up to 20 per cent, of sugar. The unripe fruit is rich in pectin and is 

 valuable in jam making. Both the leaves and also the unripe fruits are used 

 for cattle feed, the fruits being dried and ground. There are a number of 



