148 



FRUITS 



grown tast to it, and the involucre can scarcely be calit^d 



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- 



^"'^'■' 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 indehiseent fruits 

 the seed is liberated 

 by the decay of the 

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

 minating seed. Indehiseent 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, indehis(ient 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 th«se 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 

 of staminate flowers is seen in the picture. 



242. Akenes 

 of butter- 

 cup. 



