HOW FRUITS ARE FORMED 169 
The a-chene’. The seed or fruit of the sunflower is 
called an achene. The beggar needles, seeds of the 
golden-rod, etc., are also achenes. In the buttercup it 
| , is difficult for us to say just what is 
the fruit. The collection of seeds in 
the ripe or old flower is probably a 
fruit, since they are all formed from a 
single flower. Each part, however, 
-- is an achene (Fig. 210) and is gener- 
ally called a seed, though the wall of 
the seed is united with the wall of the 
pistil. An achene, then, isa ! 
dry unopening fruit, with 


a single seed the wall of 
which is joined with the 
Fic. 206. An achene or wall of the pistil. 
fruit of sunflower with The pod. The pea pod is 
four embryos in one 
seed coat, germinating. 

a good example of one kind 
of fruit. It is a capsule fruit which has 
only one chamber, or loc-ule. It opens into 
halves by splitting along the two edges. You 
can see the seeds inside, and that they are f 
attached at one point to the wall of the Fre. 27 An 
older stage 
pod. The caltha-kingcup has a fruit which ot Fig. 26. 


general application to widely different structures or combinations. We 
even speak of the fruit of ferns, meaning the spore cases and spores, 
where no seeds at all are formed. 
