226 



PLANT STRUCTURES 



izing a simple pistil, a single flower containing as many 

 pistils as there are carpels, as in the buttercups (Figs. 

 200, 202). Such a flower is said to be apocarpous, meaning 

 "carpels separate." There is a very strong tendency, 



Fig. 206. Sweet-scented shrub (Calycanthus): A, tip of branch bearing flowers; B, 

 section through flower, showing numerous floral leaves, stamens, and carpels, and 

 also the development of the receptacle about the carpels, making a perigynous 

 flower.— After Thibbault. 



however, for the carpels of a flower to organize together 

 and form a single compound pistil. In such a flower there 

 may be several carpels, but they all appear as one organ 

 (Figs. 195, C, 197, 198, 2), 199, B), and the flower is said 

 to be syncarpous, meaning "carpels together." 



124. Polypetalous to sympetalous flowers. — The tendency 

 for parts of the same set to coalesce is not confined to the 

 carpels. Sepals often coalesce (Fig. 208), and sometimes 

 stamens, but the coalescence of petals seems to be more 

 important. Among the lower forms the petals are entirely 

 separated (Figs. 199, A, 202, 203, 207), a condition which 



