58 FLOWERLESS PLANTS 



Owing to its peculiar method of spore 

 dispersal the Equisetum secures a very effective 

 distribution. Though the spores are identical in 

 appearance, yet they mostly give rise to different 

 kinds of prothalli, one of which bears the male 

 organs, and the other the female cells. It is 

 thus essential that the two kinds of spores 

 should be in reasonably close contact if a fresh 

 plant is to be the result. In this connection 

 it will be realised that the part played by the 

 threads in linking up a number of the spores 

 is a valuable one. 



Besides the Common Horsetail there are 

 three or four species of Equisetum which are 

 more or less common. One of the most impos- 

 ing is certainly the Giant Horsetail [E. maximum) , 

 which must be looked for in damp ditches, and 

 even growing up through the shallows of stag- 

 nant pools. It is not uncommon to find speci- 

 mens of this plant which may be three or four 

 feet in height. The fertile shoots, as in the 

 case of the Field Horsetail, come up before 

 the ordinary green stems, and are quite short, 

 though very sturdy in appearance. 



The Smooth Horsetail and the Marsh Horse- 

 tail {E. limoswn and E. palustre) are found in 



