The Genus Equisetum 



spores be collected and viewed through a microscope. 

 The cause of the movement, too, will be at once 

 apparent. Four fine threads with clubbed ends are 

 seen attached to the spore. If a drop of moisture be 

 now placed on the spore, the threads will become 

 invisible and will remain so, till the spore again becomes 

 dry, when the threads will once more uncoil. These 

 threads when not expanded are coiled round the spore. 

 What purpose the threads, or elaters, as they are 

 called, serve is not exactly known. 



Railway embankments, the margins and shallows of 

 ponds and marshes, ditches, roadsides, moist woods, 

 and stiff, poor soil are the favourite habitats of horsetails 

 with us. 



The British horsetails, eight in number, all belong 

 to one genus, Equisetum. The popular name, horse- 

 tail, is almost an exact translation of the botanical 

 equisetum, a word derived from equus, " a horse," and 

 seta, "a bristle." The resemblance of the upright 

 stems, more particularly the fertile stems of those 

 species which have two distinct forms, to a horse's tail 

 is alleged to be the reason why this plant is so named, 

 but the resemblance is by no means a striking one. 

 The best known horsetail is the Field Horsetail, or 

 Cornfield Horsetail, Equisetum arvense. 



It grows plentifully on railway embankments and 



roadsides, and it is very frequently found in pastures 



and cultivated land, more especially on sandy soil. 



Early in spring it sends up from a much-branched 



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