EQUISETUM. • 263 



are attached. These, on bursting, disperse a great number 

 of greenish spores. 



This species grows naturally in moist shady woods ; and 

 though local, owing apparently to the conditions necessary 

 to its growth, namely, shade and moisture combined in a 

 peculiar way, it is, nevertheless, a widely-distributed plant ; 

 and can hardly be considered as uncommon throughout 

 the United Kingdom. Its fertile stems are in perfection 

 about the middle of April, and its barren stems in June. 



Equisetum limosum, L inn cuus. 



The Water Horsetail, or Smooth NaJiecl Horsetail. 



This is a common species and generally distributed, 

 occurring principally in pools, ditches, and marshy places, 

 though occasionally in running streams. It is rather a 

 tall-growing plant, the stems rising from two to three feet 

 or more in height, springing from the joints of the dark- 

 brown underground stems, which also produce whorls of 

 black fibrous roots. The stems are, though finely ribbed, 

 very smooth to the touch, the furrows being very shallow ; 

 their smoothness no doubt arising from the presence of a 

 very slight coating of the siliceous particles, which, when 

 more abundant, give their peculiar harshness to some of 



