Clubmosses and their Relatives 



female prothallia and male spermatozoids, links the 

 Quillwort to the Selaginellas. 



There are two British species of Quillwort, but, as 

 the second is confined to the Channel Islands, it is 

 omitted here. The name, Isoetes, is derived from the 

 Greek isos, " equal or similar," and etos y " a year," and 

 is applied to the Quillwort, because it is an evergreen 

 plant. Lacustris> the specific name, is from the Latin 

 lacuSy "a lake" a quite evident reference to the 

 plant's place of growth. The popular name of the 

 plant is due to the remblance of the awl- shaped leaves 

 to quills. 



The Pillwort, or Pepperwort, the only native repre- 

 sentative of the true Waterferns, also produces larger 

 spores and smaller spores, but both are produced in the 

 the same capsule, which is four-celled, and about a 

 quarter of an inch in diameter. 



The creeping rootstock, which is only a little thicker 

 than a stout thread, is about 6 inches in length. From 

 it spring at intervals the bright-green, threadlike 

 leaves, 2 or 3 inches in length. When young they 

 are coiled like young fern fronds, but when mature 

 they straighten up. The spore capsules, which are 

 situated at the points on the rootstock from which the 

 leaves arise, are shortly stalked and covered with brown 

 hairs. 



The Pillwort is rarely met with in water or any 

 depth, preferring the margins ot ponds, ditches, and 

 marshes subject to occasional floodings. 

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