FLOWER AND FRUIT 179 
A fruit is the body produced by the development 
of the ovary and surrounding parts as a result of 
fertilisation. The ovules become the seeds and the 
wall of the ovary becomes the wall of the fruit, which 
may remain succulent or become dry and hard. The 
great functions of the fruit are to protect the seed 
and provide for its distribution. 
Fruits may be simple, aggregate or composite, 
simp!+ fruits being derived from a single carpel or a 
numver of united carpels, aggregate fruits from a 
number of free carpels, and composite fruits, not from 
a single flower but from an inflorescence. Simple 
fruits may be either dry or succulent, and dry simple 
fruits may be either dehiscent or indehiscent, 7.e., they 
may or may not open to let out their seeds. 
The achene (Fig. 115) is the type of the dry 
indehiseent form of simple fruits. It is formed from 
a one-seeded superior ovary derived from a single 
earpel, the pericarp (ovary wall) and testa are free 
from each other, and both are ruptured by the escaping 
embryo. This is well seen in the dock and sorrel, and 
in the individual members of the aggregate fruits of 
the buttercup and clematis. The following fruits are 
similar to achenes :— 
1. The cypsela is the characteristic fruit of the 
daisy family, and differs from the true achene in being 
formed from an inferior ovary derived from two 
united carpels. Its origin rather than its form con- 
stitutes the difference. 
2. The caryopsis is well seen in the wheat and maize 
gerains and the fruits of all other grasses. It differs 
from the achene in having the testa and pericarp (1.¢., 
the seed coat and seed case or ovary wall) fused 
together. | 
3. The samara is a winged achene well seen in the 
ash, elm, and ake-ake (Dodonaa). 
