222 HISTORY OF BRITISH PERNS. 



of Horsetail, a not inapt comparison with the barren fronds 

 of some of the species. 



EQUISETUM ARVENSE, Linncsus. The Corn-field Horsetail. 



This is the most common of the species, and in many 

 places is an injurious weed, very difficult to eradicate. It 

 occurs, here and there, almost everywhere in fields and 

 waste places, especially where the soil is inclined to be 

 sandy, and more abundant in moist than in dry places. 

 It has long, creeping, underground stems, which are a good 

 deal branched, and are cylindrical and jointed in the same 

 way as the stems which rise above ground. At the joints 

 they throw out whorls of tough, branching, fibrous roots. 

 The aerial stems are of two kinds, the one simple and 

 bearing the fructification only, the other branched and per- 

 fectly barren. 



The fertile stems are quite without branches, and grow 

 up early in spring, arriving at maturity and perishing long 

 before the barren ones have completed their growth. They 

 reach maturity in April and May. The stems vary, ac- 

 cording to the locality where they grow, from three to eight 

 or ten inches in height. They are hollow, succulent when 

 fresh, and of a light brown colour, nearly smooth, and ap- 

 parently without the siliceous coating common to the stems 



