CLASS XXIV. 



THE PARTS OF FRUCTIFICATION OBSCURE 

 OR UNKNOWN. 



This Class has four natural Orders* 



PRICKLY POLYPODIUM. This fern is a ° F r e d r e B r J- 

 native of most parts of Europe, and grows in shady 

 places. 



Polypodium is the botanical term for that genus 

 of plants commonly called Ferns, and of which there 

 are enumerated no less than a hundred and thirty-seven 

 species, the greater part of American growth. The 

 investigation of this extensive genus is attended with 

 difficulty from their general resemblance and habit, 

 and from the obscurity of their specific characters. 



This Class includes many genera, besides those 

 which are called ferns, in the common acceptation of 

 the word, a s Adder' s-tongue, Rough Horse-tail, Spleen- 

 wort, &c. 



M ATTED H YPNUM. The shoots of this moss o.-der ;. 

 are thickly interwoven, and form a close dark-green 

 mat on the decayed bark of trees in damp woods. 



a The botanical names of these Orders are Filices, Musci, 

 rflga, Fungi. 

 vol. II. D 



>.;s. 



