MICROSPERME^ 285 



American Waterweed, Cat's Tails, Guanner Weed, 

 Raave, Water Thyme, Thyme-weed, are the only 

 names. 



Elodea canadensis. — Note in the illustration (Fig, 

 76) the leaves in whorls, three to four in a whorl ; also the 

 long-stalked, female flowers, 



Water Soldier {Stratiotes aloides). 



It is uncertain what plant was intended by 

 Dioscorides, who bestowed the first Latin name, but 

 the leaves are sword-like, and the plant is aquatic. 

 The second Latin name refers to the Aloe-like 

 character of the leaves, which are spiny, and this 

 protects them from animals that come to drink in 

 the pools or wet places where it grows. 



It grows in the east of England, and from the 

 north of England is dispersed as far as the Midlands. 

 In Scotland and Ireland it is not indigenous but 

 naturalised. 



The habitat is ponds, ditches, lakes, fen-ditches. 

 Water Soldier occurs in the fresh-water aquatic 

 formation, in waters relatively rich in mineral salts, 

 in nearly stagnant waters, in the submerged- or nearly 

 submerged-leaf association. 



The stems are stoloniferous. The plant is sub- 

 merged or half-submerged. The stem, which is 

 short, bears roots. The plant floats up to the surface 

 in summer. It sinks again and comes up in August 

 or September. When submerged it gives rise to 



