464 



THE POLEMONIALES 



among the most characteristic features of our flora, the family 

 being largely confined in its distribution to the north temperate 

 regions. The flower of the toadflax (Linaria) illustrates a com- 

 mon type of the figwort family (Fig. 333). Such flowers are 

 said to be personate, that is bilabiate but with the under lip 

 arched so as to meet the upper lip and entirely closing the mouth 

 of the corolla. This arrangement very effectively protects the 

 microspores and conceals the nectar and it requires a rather 



m^4 ^ W 



Fig. 333. Examples of the figwort family: A, inflorescence of the toad 

 flax {Linaria). B, flower viewed from beneath, showing the under lip arching 

 up against the upper, two-lobed lip — s, nectar spur of the corolla. C, section 

 of the flower viewed from the side, showing the undivided ovary with central 

 ovules. Note the stigma and anthers concealed at the lips of the corolla. 

 D, sectional view of flower of Rhinanthus with the four stamens arranged 

 in pairs. E, appearance of the stamens as viewed from the mouth of the 

 corolla. The filaments have been pressed apart, thus separating the opened 

 anthers. 



muscular insect alighting upon the knobbed lower lip to force 

 his way into the flower. It is worth any one's time to sit by 

 this plant and examine the mechanism of the flower while the 

 bee is at work. The sporophylls present the same variety of 

 arrangements for crossing as noted in the mints. The nectar 



