SEED-BEARING PLANTS 461 
The bright shining, yellow petals vary in number from 
five to eight, and are much longer than the sepals; each 
has a little scale at its base concealing a nectar-gland. The 
simple pistils (carpels) are grouped in a round head, 
surrounded by the numerous stamens (Figs. 344 and 345). 
FIG. 344. Plant of a buttercup (Ranunctclus sp.). 
409. Spiral and Cyclic Arrangement. It will be re- 
called that in the lower type of flower, characteristic of 
the Gymnosperms, the sporophylls are arranged in spirals 
on the flower axis. A study of the flower in Angiosperms 
discloses a tendency for the flower parts to occur in 
circles; the higher the plant in the system of classification 
the more completely is the cyclic arrangement realized. 
In the Crowfoot family there are some species, especially 
