1 6 Equisetaceae 



stems 8-20 inches high, producing verticillate 

 compound branches which are curved down- 

 ward; sheaths loose and cylindric, those of 

 the stem whitish, with 8-14 rather blunt 

 brown teeth. 



In moist sandy woods and thickets in the 

 Selkirks, not common. 



Stems annual, all alike, 2-4 feet 

 Equisetum 



fluviatile L. hi g h > bluish green, smooth, usu- 

 Swamp ally producing upright branches 



Horsetail. after the spores are formed; 

 sheaths appressed with about 18 dark brown 

 or nearly black, short acute teeth. 



In sloughs and shallow ponds throughout 

 the region, frequent. 



Stems stiff, evergreen, 2-4 feet 

 Equisetum 

 byemale L. hi h > T ough f 8- 34 -furrowed, the 



Common ridges with two distinct lines 

 Scouring- o f tubercles ; sheaths rather long, 

 rush ' cylindric, marked with one or 



two black girdles, teeth dark brown or nearly 

 black and membranous, soon deciduous; 

 spikes tipped with a rigid point. 



