162 LYCOPUS, VERBENA, PLUMBAGINE&. [CHAP. 



female flowers, as well as the larger hermaphrodite 

 ones. 



Prunella vulgaris also has the two kinds of indi- 

 viduals, but the female plants are comparatively rare. 

 Axell says that, in the absence of insects, the larger 

 flowers fertilise themselves, but this was not the 

 case with those observed by Miiller. If Prunella be 

 really self-fertile this would constitute an argument 

 against Miiller's view of the origin of the small female 

 flowers. 



Lycopus Europceus is distinctly proterandrous. In 

 this species, as in Salvia, two of the stamens are rudi- 

 mentary. This is an advantage in Salvia, on account 

 of the curious mechanical structure of the stamens. 

 In Lycopus, the diminution is perhaps connected with 

 the smallness of the size of the flower. Veronica, 

 which has the smallest flowers of all the Scrophu- 

 lariaceae, has also only two stamens instead of four, 

 or more. 



VERBENACE^l. 



The common Verbena officinalis is the only British species of this 

 order. The calyx is five-toothed, the corolla distinctly tubular, and 

 with five somewhat unequal lobes. The stamens are sometimes two, 

 sometimes four, in number. It secretes honey at the base of the tube. 



PLUMBAGINE^. 



There are two British genera of this order, viz. Statice and Armeria. 

 The genus Plumbago has already been referred to in the introductory 

 chapter (antt, p. 10) as an illustration of an insect-fertilised flower, in 

 contrast with Plantago major, which is wind-fertilised. 



