CHAPTER XIII. THE FRUIT AND SEED. 



IO9 



tant aid to the dispersion of their seeds, as it attracts the atten- 

 tion of fruit-eating animals, and causes the fruits to be eaten, or 

 at least to be plucked and tasted. But many fruits and seeds 

 are provided with hooks, spines, barbs, adhesive pericarps, or 

 other means by which they cling to the bodies of animals, and 

 are thus scattered. Fruits of the Burdock, Bidens, Stickseed, 

 Tick-trefoil and Mistletoe are illustrative examples, and many 

 others might be educed. Fig. 308 and 309 represent, respectively, 

 the fruits of species of Martynia and Bidens. 



Classification of Fruits. — Although the following scheme 

 of classification does not claim completeness, it includes the 

 most important forms of fruits, and for practical purposes will be 

 found convenient. 



Fig. 310. 



Fig. 



? i: 



Fig. 312. 



Fig. 313. 



Fig 310. — Superior achenium of Ranunculus, with portion of ovary wall removed to 

 show internal structure. 



Fig. 311 — Inferior achenium of Sow Thistle. 

 Fig. 312. — Caudate achenium of Clematis. 

 Fig. 313. — Utricle of Chenopodium. 



They are primarily divided into two groups, those which are 

 the product of a single flower, and those which are the product 

 of a flower cluster. 



The former kind are subdivided into those which are the 

 product of one pistil (either apocarpous or syncarpous), and 

 those which are the product of more than one. The former of 

 these subdivisions is divided into indehiscent forms, or those 

 which do not split open when ripe, and dehiscent forms, those 

 which do. The most important of the indehiscent forms are the 

 following : 



(1) The Akene or Achenium. This is a one-seeded, dry, 

 hard, seed-like fruit, like that of the Ranunculus, shown in Ion- 



