158 



PLANTS OF THE ALPINE MEADOWS 



Britain, this plant flourishes chiefly in marshes and 

 wet ditches. 



The drooping flowers, with dusky red petals, are 

 interesting from several points of view. Like the 

 Potentillas, this plant possesses a double calyx. The 

 outer five sepals, known botanically as the epicalyx, 



Fig. XIV.— Stages in the development of the Fruit of the Water Avens 

 {Oeum rivaUy Linn.). 



are small, and alternate in position with the five larger 

 inner sepals. 



The fruit of the Water Avens (Text-fig. XIV.) 

 furnishes material for an interesting study. It is 

 especially adapted for distribution by animal agency. 

 Each of the carpels grows out into a long awn as 

 the fruits matui^e. A well-marked hook is developed 



