on British Ferns. xv 



Genus. — Polystichum, Schott. 



Involucre circular, scale -like, its margins free, attached 

 by its centre : first upper pinnule of each pair gTeatly lar- 

 ger than the second, and larger than the first and second 

 lower pinnules ; all the ultimate divisions ending in an 

 acute spine. 



Obs.—The genus Poljstichum, as proposed by Both, is almost iden- 

 tical with Aspidium of Willdenow, but was subsequently restricted by 

 Schott to the typical species, and those having a similar chcular invo- 

 lucre. Although as regai'ds British species the genus thus restricted 

 is remarkably distinct, yet among exotic ferns we fuid species almost 

 precisely mtermediate between this and the followmg genus. 



Polystichum angulare. 



Polypodium aculeatum, Light/. Fl. Scot. 675 ; Huds. Fl. 



Ang. 459. 

 Aspidium angulare, Willd. Sp. PL v. 257 ; Sm. E. F. iv. 

 291, E. B. S. 2776 ; Mack. FL Hib. 339 ; Hook, and 

 Am. 568. 

 Polystichum angulare, Neum. N. A. 25, F. 173 ; Bah. 412. 

 Ehizoma tufted ; stipes one-third as long as the frond, 

 densely clothed with large, red, chafiy scales ; frond droop- 

 ing, graceful, broad lanceolate, lax, feathery, pinnate; pinnse 

 very numerous, linear, distant, pinnate ; pinnules distinct, 

 stalked, often distant, auricled at the base, rounded at the 

 apex, serrated, spined. 



Common in woods and shady lanes. 



Polystichum aculeatum. 



Polypodium aculeatum, Linn. Sp. PI. 1552. 



Polypodium lobatum, "aflfinis prsecedenti (P. angulare, I. c.) 

 an distincta sit species ? " Htuls. Fl. Ang. 469 ; With. 

 Bot. Arr. Veg. 651. 



Polipodium aculeatum. Bolt. Fil. Brit. 48, t. 26. "Polipo- 

 dium lobatum. Hall. Hist. 1712, and Fl. Ang. 459, is 

 doubtless a young plant of Polipodium aculeatum ; of 

 tliis I am certain from observation." — Bolt. I. c. 



