BORAGINE^ 293 



BCHIUM 



E. vulgare (Viper's Bugloss) has generally protandrous 

 flowers. The honey is abundant. From the size and 

 bright colour of the flowers, and their association in a 

 long one-sided inflorescence, they are very conspicuous, 

 and much visited by insects, nearly 100 species being on 

 record. The lower parts of the filaments are soldered 

 to the corolla-tube, and where they detach themselves 

 the tube suddenly enlarges, so that even the largest 

 humble bee can conveniently insert its head and 

 thorax. Four of the- stamens lie along the under side of 

 the flower ; one, on the contrary, is separate, and divides 

 the tube into two parts. The anthers open with the 

 flower, and turn the pollen upwards. When the flower 

 opens, the pistil is somewhat shorter than the corolla-tube, 

 but it soon elongates and projects beyond the stamens. 

 This is one of the flowers which changes colour ; ^ from 

 reddish purple they become bright blue. Besides these 

 complete flowers, plants occur with smaller flowers, in 

 which the stamens are short and the anthers without 

 pollen. Intermediate forms also occur. The plant is effec- 

 tively protected by stiff, spreading, almost prickly leaves. 



E. violaceum, which occurs in Cornwall, is of interest 

 from its geographical distribution. It belongs to that 

 Southern European element, examples of which occur in 

 our flora only in the West of England. 



PULMONARIA 



Nectar secreted by the base of the ovary, and pro- 

 tected by hairs on the inside of the corolla. Corolla- 

 tube straight. 



P. officinalis is a European species, rare in Britain, 

 where it has become naturalised in woods and copses in 

 the South of Scotland and England. The flowers, which 

 are borne in a terminal forked cyme, are first red, then 

 blue- violet; they are dimorphous; the tube is 10-12 mm. 

 long, but as it is large enough at the summit to admit 



1 See p. 84. 



