222 THE AQUATIC QUILLWORTS. 



appear to be trivial ones produced by the habitat in 

 which they grow. Most botanists now give little atten- 

 tion to them. According to Eaton Doottii is found in 

 sand, and this may account for its characteristic slender 

 leaves. 



Isoctes ecliinospora umricata is a more pronounced form. 

 The leaves are longer, slenderer, and 

 inclined to be spiral and the mega- 

 spores are slightly larger, and covered 

 with shorter, thicker, and more con- 

 fluent spinules. In deep water the 

 slender leaves are inclined to take on 

 a spiral form. This variety is found 

 ^ rom Nova Scotia to New Jersey. 

 hoetcs ecJiinospora Flcttii comes from a 

 few lakes in Washington and British 

 Columbia, and differs from the type in having stout 

 leaves, and the spines of the megaspores few, very short, 

 almost wart-like. This is an extreme form and by some 

 might be considered a distinct species. In spore char- 

 acters it approaches the various other species of the 

 Northwest, and except for the size of the spores might 

 be considered a variety of Isoctes Bolandcri. 



A stout plant, also from northwestern 

 America, has been named Isoctes ecJiino- 

 spora truncata. This has megaspores 

 thickly covered with short truncate 

 columns. The spores are noticeably 

 flattened on the hemispheres contain- 

 ing the commissures, and are not 



I r i 1 i r Isoctcs truncata, 



easily confused with those of other 



species. This form is reported from Vancouver Island 



to Alaska, but is as yet not common. The author would 



