DEVELOPMENT OF PLANTS 



45i 



154. Campanulales, the Bellflower Order. — This order marks 

 the culmination of the tendencies that we have seen steadily 

 progressing through the monocotyledons and the dicotyledons. 

 The variations have been of so peculiar and successful a nature 

 that no group of plants are so widely distributed and in the 

 more specialized families of so common occurrence. Over 

 14,500 species are known. The parts of the epigynous flowers 

 are arranged in four whorls of usually five members each. The 

 anthers are aggregated and usually cohere, forming a sheath 



Fig. 337. Lower forms of the Campanulales : A, inflorescence of the 

 bellflower {Campanula). B, section of «a young flower. The hairy style 

 is pushing up between the encircling anthers and sweeping the spores out 

 of them. Note the closed stigmatic lobes. C, older flower. The anthers 

 are withering and the stigmas are curving back towards the spore-covered 

 style. D, flower of Lobelia. The tubular corolla is opened at one side, 

 permitting the style and encircling stamens, g, to protrude. E, section oT 

 flower, showing the anthers, a, united about the style and stigma. F, rela- 

 tion of stigma to anthers. At right the section shows the anthers cohering 

 about the bushy style, which acts later as a brush sweeping out the spores. 

 At the left the style has grown beyond the anthers and the stigmatic lobes 

 are spreading apart. 



