THE BRITISH PEPPERWORTS. 



103 



give it a bluntly quadrangular section. There is but one 

 species, the I. lacustris, a stemless quill-leaved submerged 

 plant, which gives the appearance of a green turf to the 

 bottom of the water where it occurs. 



Pilularia., the Pillwort or Pepper-grass, differs consider- 

 ably from Isoetes in the parts of fructification ; for while in 

 Isoetes the spore-cases are within the thickened bases of the 

 leaves ; in Pilularia they are quite free, and attached directly 

 to the stem, though seated at the base of a small tuft of 

 leaves ; they also differ in structure, that of Isoetes consisting 

 of granular and pulverulent spores, occupying ; separate spore- 

 cases, while in that of Pilularia the two kinds of spores are 

 produced within each spore-case, the larger bodies occupying 

 principally the lower, and the 

 smaller ones the upper parts. Its FlG - 28 - 



name comes faompilula, signify- 

 ing a little pill, the spore-cases 

 having a nearly globular form. 



THE EUROPEAN QU1LLWORT, OR 



MERLIN'S GRASS. 



This is the Isoetes lacmtris of 

 botanists, a very curious plant, 

 growing at the bottom of moun- 

 tain lakes, and having so much 

 the appearance of submerged 

 grass, that the inexperienced eye 

 would probably pass it by unno- 

 ticed. It has a fleshy tuber, nearly 

 globular in form, white and com- 



Sact internally, but spongy and 

 ark-brown coloured on the out- 

 side. The leaves spring up from the 

 crown of these tubers, and grow 

 erect to the height of four or six 

 inches, or more ; they are persist- 

 ent, and of an olive-green colour, 

 and their general form is awl- 

 shaped, with the basal portion 

 dilated ; above which dilated part 

 they are bluntly quadrangular, 

 being formed of four parallel hol- 

 low tubes, which taper off towards 

 the apex, and terminate in a sharp 

 point, 



lilies lacKttrit. 



