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THE BRITISH PEPPERWOETS. 



The group of plants to which the name of Pepperworts 

 has been given, is technically called Marsileacece, and 

 contains but a few genera, these being of very curious 

 structure. It has only two representatives in the British 

 flora. These two plants belong to different genera, and 

 are both submerged aquatic plants of small size, agreeing 

 in having grassy or quill-like foliage, but differing mate- 

 rially in habit, the one being of creeping habit and the 

 other tufted. The fructification also presents some mate- 

 rial differences, on which account Isoetes is sometimes 

 classed with the Club-mosses, instead of the Pepperworts. 



Genus XXII. ISOETES, or QUILLWORT. 



Isoetes, which takes its name from the Greek words isos, 

 equal, and etos, the year, on account of its retaining its 



