148 



FRUITS 



grown fast to it, and the involucre can scarcely be called 

 a part of the fruit. A ripened ovary is a pericarp. A 

 pericarp to which other parts adhere, has been called an 



accessory or rein- 

 forced fruit. 



287. Some fruits 

 are dehiscent, or split 

 open at maturity(264) 

 and liberate the seeds; 

 others are indehis- 

 cent, or do not open. 

 A dehiscent pericarp 

 is called a pod. The 

 parts into which such 

 a pod breaks or splits 

 are known as valves. 

 In indehiscent fruits 

 liberated 

 by the decay of the 

 envelope, or by the rupturing of the envelope by the ger- 

 minating seed. Indehiscent winged pericarps are known 

 as samaras or key-fruits (consult Chapter XXII). Maple, 

 elm (Fig. 93), and ash (Fig. 127) are examples. 



288. PERICARPS. The simplest pericarp is a dry, one- 

 seeded, indehiscent body. It is known as an akene. A 

 head of akenes is shown in Fig. 242, and the 

 structure is explained in Fig. 191. Akenes may 

 be seen in buttercup, hepatica, anemone, 

 smartweed, buckwheat. 



289. A 1-loculed pericarp which dehisces 

 along the front edge (that is, the inner edge, 

 next the center of the flower) is a follicle. The 

 fruit of the larkspur (Fig. 243) is a follicle. 

 There are usually five of these fruits (sometimes three 

 or four) in each larkspur flower, each pistil ripening into 



241. Chestnuts are ripened ovaries. They are borne in 



a prickly involucre. The remains of the catkin fl, 000/"] ic 

 of staminate flowers is seen m the picture. 



242. Akenes 

 of butter- 

 cup. 



