88' FRUIT 



Wallflower is slightly more complicated, in that the ovary is 

 syncarpous, being composed of two carpels ; but in this flower, 

 as in the Pea, it is the single ovary alone which, by its growth, 

 gives rise to the single fruit (fig. 120). The Buttercup differs 

 from the two preceding examples in that every flower has a 

 number of separate ovaries, each representing one carpel. Each 

 ovary enlarges and eventually encloses one seed (fig. 115)- 

 This flower thus gives place to a number of apocarpous seed- 

 containing vessels, each similar to the pea-pod in so far as it 

 consists of a single ripened carpel. We can, therefore, divide 

 fruits into two groups : (i.) Simple fruits, produced by a single 

 ovary which is composed of one {e.g. Pea) or more carpels 

 {e.g. Wallflower), (ii.) Compound fruits, produced by a 

 number of apocarpous carpels in one flower {e.g. Buttercup). 

 Thus the fruit of a Buttercup is a compound fruit and consists 

 of a number of simple fruits. 



The external wall of the chamber, or chambers, of a simple 

 fruit is termed the pericarp. In the case of the simple fruits 

 already mentioned, the pericarp is derived solely from the 

 carpels ; it is the original wall of the ovary, which has grown. 

 But if we consider a'simple fruit derived from a single inferior 

 ovary {e.g. Honeysuckle, Parsley, Yellow Flag, Orchid), the 

 wall of the fruit represents part of the receptacle as well as 

 portions of the carpels (see p. 75). 



Again, if we examine a ripened (fertilised) Dandelion-head 

 (fig. 129), we shall see that it consists of a number of simple 

 fruits. Every one of these is formed by the growth of a single 

 inferior ovary, each of which belongs to a separate flower. 

 This Dandelion-head is formed as a result of the fertilisation 

 of a number of flowers. A fruit is formed frqm one flower, 

 consequently the Dandelion-head' is not a fruit, not even a 

 compound fruit: it is a collection of fruits, or an infruct- 

 escence. 



Comparing the behaviour of the pericarp, of the simple fruits 

 of the Pea, Wallflower, Buttercup, and Dandelion, we see 

 that the pericarp of the first two gapes open, or dehisces, when 

 it is ripe, so that the carpels are freely open ; whereas, on the 

 contrary, the fruits of the last two do not open of their own 

 accord. If we now examine the fruit of a Parsley-plant (or any 

 Umbellifer), we note that it is formed by a single inferior, two- 

 chambered ovary, composed of two carpels. When the fruit 



