254 BRITISH FLOWERING PLANTS chap. 



glomerata, etc.), which, have short stalks, and cannot 

 therefore turn over, the flowers themselves close. In 

 the absence of insect visits the greater number are 

 capable of fertilising themselves ; the pollen reaching 

 the stigmas partly through the folding of the corolla, 

 partly by the rolling back of the stigmas themselves. 



Lobelia 



The corolla is irregular, open on the upper side. 

 The pollen is shed into the anther-tube, as in Com- 

 positae, and is swept out by the brush of the stigma. 

 We have two species — one, L. Dortmanna, an aquatic 

 plant with drooping flowers ; the other, L. urens, a 

 heath plant with erect flowers. They do not seem to 

 be much visited by insects, but have not been carefully 

 watched. 



In L. urens the stem is angular, and the plant 

 puberulent. It is a South-west European species, which 

 finds its northern limit of distribution in the West of 

 England. 



L. Dortmaana is aquatic and glabrous. The leaves 

 are doubly flstular ; that is to say, they are divided into 

 two longitudinal tubes. 



Jasionb 



Corolla regular, deeply divided into five narrow 

 lobes. The anthers form a tube into which the pollen 

 is shed. 



J. montana (Sheep's-bit). — This species has been well 

 described by Sprengel. The heads consist of 100-200 

 pale-blue florets. It is one of the flowers most richly 

 visited by insects, being, indeed, surpassed only by a 

 few Umbellifers and Composites. The association of 

 the florets into heads, the convenient position and rich 

 supply of nectar, and the arrangement of the flower, all 

 contribute to this result, and about 150 species of insect 

 visitors are on record, of which over 50 are bees, 30 

 butterflies and hawkmoths, and 30 flies. Perhaps in 

 consequence, the power of self-fertilisation is apparently 



