228 



PLANT STEUCTUKES 



ated into two regions (Fig. 210, b), a more or less tubular 

 portion, the tube, and a more or less flaring portion, the limb. 



125. Actinomorphic 

 to zygomorphic flow- 

 ers. — In the simpler 

 flowers all the mem- 

 bers of any one cycle 

 are alike ; the petals 

 are all alike, the 

 stamens are all alike, 

 etc. Looking at the 

 center of the flower, 

 all the parts are re- 

 peated about it like 

 the parts of a radi- 

 ate animal. Such a 

 flower is actinomor- 

 phic, meaning "ra- 

 diate," and is often 

 called a " regular 

 flower." Although 

 the term actinomor- 

 phic strictly applies to all the floral organs, it is especially 

 noteworthy in connection with the corolla, whose changes 

 will be noted. 



Fie. 209. Flower of morning-glory (Ipomcea), with 

 sympetalous corolla split open, showing the five 

 attached stamens, and the superior ovary with 

 prominent style and stigma ; the flower is hy- 

 pogynous, sympetalous, and actinomorphic— 

 After Meissneb. 



Fig. 210. A group of sympetalous flower forms: a, a flower of harebell, showing a 

 bell-shaped corolla; b, a flower of phlox, showing a tube and spreading limb; c, a 

 flower of dead-nettle, showing a zygomorphic two-lipped corolla; U, a flower of 

 toad-flax, showing a two-lipped corolla, and also a spur formed by the base of the 

 corolla; e, a flower of the snapdragon, showing the two lips of the corolla closed. 

 —After Gray. 



