ALLOSOKUS CRISPUS. 



39 



§mx^M. 



The principal characters by which 

 to distinguish this plant from other 

 British Polypodies, are, that its 

 fronds are both barren and fertile, and 

 that the margins of the pinnules in 

 the fertile frond are infiexed or con 

 volute, covering the clusters of cap- 

 sules. I have to acknowledge my 

 obligation to the late Mr. Samuel 

 Gibson, as well as to Miss Beever 

 and Mr. Cruickshank, for fronds par- 

 tially fruited and partially barren. 



The radicles are fibrous, numer- 

 ous, tough, and adhere tenaciously to 

 the earth or stones : the caudex is 

 procumbent, extending itself hori- 

 zontally, and producing a constant 

 succession of fronds from its crown : 

 this procumbent or horizontal posi- 

 tion appears to me rather the result 

 of age, or want of power to maintain 

 an erect position, than of a tendency 

 to a creei^ing habit. The fronds rise 

 in May and June, and disappear at 

 the commencement of winter : as 

 before stated, they are of two kinds, 

 fertile and barren, both being nearly 

 triangular in form, and, like the frond 

 of Adiantum Capillus-Veneris, they 

 are composed of numerous, leaf- like, 

 ultimate divisions : the pinnee, pin- 

 nules, and ultimate divisions, are 

 arranged alternately : the stipes is 

 slender, smooth, pale green, and 

 is generally much longer than the 

 « frond, which is of a bright and de- 

 licate green colour. The ultimate 



