230 FIELD AND WOODLAND PLANTS 



often three small teeth, while the lower is divided into ^wo lobes ; 

 and the corolla is of a bright blue colour, about three times as long 

 as the calyx, with a long, arched upper hp and a three-lobed lower 

 lip. There are two stamens, each with a fertile and an abortive 

 anther connected by a thin stalk which is fastened to the short 

 filament in such a manner that it rocks. This plant flowers from 

 June to August. 



The peculiar arrangement of the stamens above described is 



The Small BrNDWEED. 



sufficient in itself to distinguish the genus Salvia from all the other 

 Labiates, and the importance of the pecuKarity in connexion with 

 the polhnation of the flower is so interesting that we may well 

 spend a few minutes in studying it before passing on to other species. 

 In the first place it should be mentioned that the stamens of Salvia 

 are mature before the stigma, and that, as a consequence, self- 

 pollination is impossible. The lower, abortive anthers of the two 

 stamens are joined together and form a little valve which closes 

 the throat of the corolla tube. Each one, however, has a notch in 

 its inner side, and the two notches, meeting in the middle, form a 

 little hole. When a bee visits the flower, it alights on the lower lip 



