CLASSIFICATION OF ANGIOSPERMS. 567 



the wild strawberries the fruit is smaller, usually somewhat flesh- 

 colored and the achenes are either embedded in the torus as in -F. 

 I'iryiniana or borne on the surface as in F. vesca. The strawberry 

 fruit contains about 87 per cent, of water; 6 per cent, of cane 

 sugar; 5 per cent, of invert sugar (a mixture of dextrose and 

 levulose) ; i per cent, of free fruit-acids; and about 2 per cent, 

 of nitrogenous substances. 



g. LEGUMINOS^: OR PULSE FAMILY. The plants are 

 herbs, shrubs, trees, or vines with alternate, stipulate and usually 

 compound leaves. The flowers are complete, and the corolla is 

 either regular or irregular; the stamens are usually united, and 

 the pistil is simple and free, becoming in fruit a legume. The 

 plants are widely distributed, many of them being found in the 

 Tropics. Three principal sub-groups, which have been ranked 

 as families by some botanists, are recognized. 



1. PAPILIONAT^:. Those species with papilionaceous flowers 

 are separated into a group called the Papilionatae. This sub-group 

 has a number of representatives in the United States, as clover, 

 locust, and Baptisia (Fig. 280, L). 



2. OESALPINIOIDE/E include the sennas and have flowers which 

 are nearly regular, or imperfectly, or not at all papilionaceous. 



3. The MIMOSOIDE^E include the acacias and have flowers that 

 are regular. 



Cassia acnti folia is a small shrub with leaves that are 8- to 

 lo-foliate. The leaflets are official as Alexandria or Tripoli senna ; 

 the flowers are yellowish and in axillary racemes ; the fruit is a 

 smooth, flat, dehiscent pod, with 6 to 8 seeds. 



Cassia angustifolia is a shrub which is cultivated in Southern 

 India and resembles Cassia acutifolia. The leaflets which consti- 

 tute India senna or Tinnevelly senna are longer and narrow-lanceo- 

 late, and the pods are longer, and slightly crescent-shaped, as 

 compared to those of C. acutifolia. 



Cassia Fistula or purging cassia, the pods of which are used 

 in medicine, is a tree about 15 M. high. The leaves are 10- to 12- 

 f oliate ; the flowers golden-yellow and in racemes ; and the fruit 

 is a very long, cylindrical, indehiscent legume. The leaves of 

 quite a number of species of Cassia are used in medicine and the 



