366 TEXTBOOK OF BOTANY 



A large number of simple dry fruits are many-seeded and dehiscent. 

 The legumes of the pea and the bean split along two sutures: the fol- 

 licles of milkweed and larkspur split along one suture; the capsules of 

 tulip, cotton, and okra consist of more than one carpel and split along 

 several sutures. The ptjxis of plantain, purslane, and pigweed splits 

 crosswise. 



Representative examples of some of the more familiar complex fruits 

 are the apple and the cucumber, the raspberry and the strawberry, and 

 the mulberry and the pineapple. 



The fruits of apple, pear, quince, hawthorn are called pomes. The core 

 resembles a drupe in that the cartilaginous part is the inner layer of the 

 ovulary and is surrounded by a soft juicy layer that develops from the 

 outer tissue of the ovulary. Most of the edible part, however, develops 

 from the floral cup. 



The fruit of the cucumber likewise develops from the ovulary and 

 adherent floral cup, but does not have the inner cartilaginous tissue. 

 Other examples are gooseberry, currant, cranberry, blueberry, banana, 

 pomegranate, guava, coffee, gourd, pumpkin, squash, muskmelon, and 

 watermelon. 



In each pistillate flower of a strawberry are many separate pistils on 

 an enlarged receptacle. As the receptacle enlarges and becomes the 

 major part of the fruit, the pistils ripen as separate akenes and are partly 

 embedded in the receptacle. Because of this assemblage of pistils on 

 one receptacle the strawberry is called an aggregate fruit. Other examples 

 are blackberrv and raspberrv, in each of which the separate pistils ripen 

 as small drupes, or drupelets. When a raspberry is ripe the closely 

 adhering aggregate of drupelets separates from the receptacle. In the 

 fruit of wild roses the group of ripened pistils is enclosed by a floral cup. 



When fruits from several flowers are united in a compact mass, the 

 entire assemblage is a multiple fruit. The formation of multiple fruits 

 varies with the kind of plant. In the fruit of the fig the enlarged fleshy 

 receptacle is hollow, and on its inner surface there is a compact layer of 

 simple fruits that de\'eloped from the enclosed flowers. The flowers of 

 the pistillate catkin of the mulberry surround the floral axis in a compact 

 mass as the sepals become thickened and succulent. The multiple fruit 

 of pineapple also develops from a spike-like cluster of flowers in which 

 the floral axis, flowers, and subtending bracts all become enlarged and 

 united in a single mass (Fig. 163). 



