18 ASPIDIUM, § POLYSTICHUM. 



authentic specimens of //. macrosorum, Fee (Schlim, New Granada, n. 658), do 

 not exhibit the shadow of a difference from spmicordatvm. The fronds, although 

 apparently articulated upon the rachis, and although the ddated base of the short 

 petiole has a dark mark and a depression around it, as if the pinnne would fall 

 away there, yet in all my numerous specimens the latter are singularly persistent. 



*** Fronds bi- rarely tri-pinnate. 



22. A. (Polystichum) acuIeafum,Sw.; caudex short suberect, 

 stipites tufted and rachises more or less clothed with ferrugi- 

 nous scales of two forms, one slender and resembling hairs, 

 on the stipes especially, mixed with large ovate or lanceolate 

 ones sometimes two-coloured, fronds 1-2-3 feet long oblong- 

 lanceolate acuminate sometimes proliferous bi- rarely tripin- 

 nate subcoriaceous, primary pinnce approximate from abroad- 

 ish subpetiolated base oblong- or linear-lanceolate subfalcate, 

 pinnules close subrhombeo-ovate or lanceolate free subpe- 

 tiolulate or decurrent at the very base with the adjacent ones 

 spinosely or setosely serrated or lobate, the superior base 

 more or less auricled, sori generally in two rows on each 

 pinnule and usually nearer the costa than the margin, costse 

 and costules more or less villoso-paleaceous beneath. — Poly- 

 podium aculeatum, Linn. 



Hah.* Almost every part of the known world : — 



1. Throughout Europe. As Linnaeus descril)ed his Polypodium aculeatum, 

 Linn. Sp. PL p. 1552, from European specimens, " Ilab. Europa," and as he 

 had but one species of this group in view (since extended to three), it is but 

 reasonable to consider that the type of the species. We may then add Aspi- 

 dium aculeatum. Bent. Hand. Brit. Flora, p. 628, and Hook. Brit. Ferns, tt. 

 10, 11, 12. A. lobatum, Metten. Aspid. p. iS. The pinnules are variable, and 

 hence chiefly three species have been formed by European Botanists, viz. : 1. As- 

 pidium aculeatum, Sin. in Schrad. Journ. 1800, ii. p. 37, and Syn. Fil. v. p. 258 

 (the frond rigid, but submembranaceous ; pinnules subsessile, more or less 

 auricled ; serratures spinulose). Schkh. Fil. t. 39 : very good. TJ'illd. Sp. PI. 

 v. p. 258. Srn. F. Brit. p. 1122. Etigl. Fl. iv. p. 277. Engl. Bot. t. 1662. 



* With my perhaps peculiar views of the universal distribution of this species 

 which has been described under so many different names in the Floras of diffe- 

 rent regions, I should despair of making myself intelligible unless I include the 

 synonyms under the different countries they inhabit ; and these localities I shall 

 take almost exclusively from specimens preserved in my own herbarium. I siiall 

 offer a few remarks as I proceed, in order to explain my reasons for thus uniting 

 so many species which have been preserved by many able botanists as distinct. 

 It is certain that the very extensive suites of specimens in my possession give me 

 an advantage in forming an opinion, such as perhaps none of my predecessors or 

 cotemporaries have enjoyed ; but I am compelled to omit a considerable number 

 of synonyms of very trustworthy authors, because of the difficulty of ascertain- 

 ing the exact forms they intend, or to admit them only with a doubt. 



