W158 



WESTERN BRACKEN 



Pteri'dium aquili'num pubes'cens, syns. "Pte'ris aguili'na", 1 Pte'ris aquili'na 



lanugino'sa 



Leaves large (up to 4 ft. long), 

 much divided, somewhat tri- 

 angular in outline, slightly hairy 

 above and markedly so beneath 



Main leaf divisions (pinnae) 

 numerous, divided (usually pin- 

 nately compound) 



Smallest leaf-divisions (pin- 

 nules) with margins entire, 

 notched, cleft, or sometimes 

 again divided, of 2 kinds similar 

 in appearance: (1) "seed"- 

 producing, and (2) not "seed"- 

 producing 



Leafstalk usually solitary, 

 erect, up to 4 ft. high, stout, 

 dark-colored below but becom- 

 ing straw-colored above, swollen 

 and with feltlike covering at 

 base, not jointed at point of 

 attachment with rootstock 



Fertile pinnule with a margi- 

 nal ridge beneath, from which 

 a row (linear sorus) of stalked 

 "seed" cases (sporangia) grows, 

 both ridge and sorus covered by 

 a narrow feltlike double mem- 

 brane (indusium) partly formed 

 by curved-under edge of leaf 



Sporangia microscopic in size 

 but so numerous that they 

 appear as brown masses of 

 "rust", each with incomplete 

 vertical ring of thick-walled, 

 water-absorbing cells by which 



rrangium opens to discharge- 

 "seed" (spores) 



Rootstock deep underground, 

 cordlike, woody, dark-colored, 

 extensive, often much branched 



Roots numerous, 

 wiry, dark-colored 



fibrous, 



Above ground the plant consists of but a single, very large leaf (frond) which has a leaf- 

 stalk (stipe) below and a very much divided leaf blade above. As in all ferns, no 

 flowers are produced. 



1 Of western authors. 



