1059 



throughout. The spike of E. liraosum is thick, black, and spongy, 

 as is well represented in Newman's figure,* and is usually sessile, the 

 uppermost sheath clasping it like an involucre. It expands earlier in 

 the season than that of E. fluviatile, which is smaller in size, more 

 slender and graceful, lighter in colour, and usually elevated from its 

 sheath upon a fragile stalk. In order to afford a more precise idea of 

 the habit and dimensions of E. fluviatile than can be conveyed in a 

 general description, I have selected, for purpose of illustration, from 

 a bundle of specimens collected in this neighbourhood, four average 

 stems, which may convey some idea of its leading and most frequent 

 states of variation. 



A is a barren stem, measuring fifty inches in length, and, at its 

 broadest portion, when pressed flat, three lines in breadth. It is 

 curved considerably towards the summit, and tapers gradually, the 

 thirtieth internode being exactly half the width of the twelfth. It has 

 forty-one joints, the spaces between which, in its three lowermost 

 quarters, vary in length from one inch to one and a half. All the 

 nodes from the first to the fifteenth inclusive are branchless ; the 

 sixteenth has one branch, seven inches in length, with twelve joints ; 

 the seventeenth, one ; the eighteenth and nineteenth, two each ; the 

 twentieth, one ; the twenty-first, none ; the twenty-second, two ; but 

 the remainder are branchless : in all, nine branches, of which the 

 shortest is four inches in length. 



B is a barren stem, forty-one inches in length, rather more slender 

 than in the last. It has thirty-six nodes above those from which the 

 roots issue. From the thirteenth of these issues a branch, five inches 

 and a half in length ; the fourteenth is branchless ; the fifteenth has 

 three branches ; the sixteenth, six ; the seventeenth, ten ; the eigh- 

 teenth, nine ; the nineteenth, two ; the remainder are branchless ; 

 total, thirty-one branches. 



C is a barren stem, fifty inches in length, equalling the first in 

 breadth. It has forty nodes above those from which the roots issue. 

 Of these, the first to the thirteenth inclusive are branchless ; the four- 

 teenth has a single slender branch ; the fifteenth, one ; the sixteenth, 

 eleven ; the seventeenth and eighteenth, fourteen each ; the nine- 

 teenth, twelve ; the twentieth, thirteen ; the twenty-first, seventeen ; 

 the twenty-second, fourteen ; the twenty-third, eight ; the twenty- 

 fourth, four ; the remainder are branchless : total number of branches, 

 one hundred and nine, averaging two inches and a half in length. 



* Hist. Brit. Ferns, 2nd ed. p. 61. 



