THE ROELLA AND LOBELIA FAMILY. 171 



at the base, in Wahlenhcr' gia they are at the top of the 

 ovary, and by valves. Eoel'la has no valves. 



Lightfoot'ia. — The capsule of this has five valves, 

 but the corolla is almost itolypetalous^ i.e. with the 

 petals nearly free. There are twenty- five species. 



Prismatocar'pus. — This has fourteen species, and its 

 capsule splits from top to bottom. 



Lobe'lia. — This is a large genus scattered over the 

 world, twenty-six species being in South Africa. It 

 differs from the preceding in having an irregular corolla 

 (Fig. 72). 



The method of pollination agrees with that described 

 for Composites. 



The calyx has five sepals, and is superior, the ovary 

 being inferior. The corolla of five petals is epigynous, 

 being "upon the ovary." The stamens are five in 

 number (V.), coherent by their anthers, or syngenesious 

 (III.). Some of the filaments usually cohere slightly 

 to the corolla (II.). The style has a ring of hairs just 

 below the two stigmas, which are pressed together at 

 first (IV.). By the style elongating the hairs sweep 

 the pollen upwards, and bring it out beyond the anthers, 

 just as in Composites. 



When the stigmas separate, they are ready to receive 

 any pollen brought by insects from some other flower, 

 as the pollen, being behind the stigmas, will not readily 

 reach them, if at all. Hence, Lobelia is a regularly 

 insect-fertilized flower. 



