100 



" Var. (S. dilatatum, K. Polypodium dilatatum, Hoffm. Frond 

 1 — 2 ft. high, lively green, bipinnate and pinnatifid, almost tripinnate, 

 deltoid-ovate in its outline. With the species, especially in shady 

 woods. 



" 1st remark. — The most widely different forms of this fern are found 

 on the hill of Montabaurer, distant three hours' journey from Coblentz, 

 1600 feet high, in the dukedom of Nassau, which affords an especially 

 rich harvest in ferns, and the present species in great quantity on sunny 

 and shady, stony and fertile, dry and boggy, ground. I usually found 

 the variety at the end of October dead and black, while the species 

 was still of a lively green or a yellowish green. 



" 2nd remark. — The species and the variety have been regarded by 

 many authors as two distinct species ; and they really appear so dif- 

 ferent, that when the variety is seen without its intermediate forms, it 

 may well be taken for a distinct species ; but on further research such 

 a host of intermediate forms occur, that one is often at a loss to know 

 to which of the two principal forms they should be referred. Accord- 

 ing to Schkuhr, Kaulfuss, Spenner, Wallroth, Genth, and others, 

 P. spinulosum should possess a glandular, and P. dilatatum a smooth 

 [indusium?] ; which, on the contrary, is questioned by Lejeune and 

 Courtois, Link, Meyer, Roper, and others, neither have I met with the 

 glandular indusium in any of the forms. John Roper has most 

 thoroughly investigated the history of this species in his excellent 

 work ' Flora Mecklenburgs,' vol. i., pages 82 — 96, and, moreover, also 

 unites with it P. cristatum, which I nevertheless was unable to con- 

 firm. 



" He distinguishes — 



" 1. Principal or intermediate form : Nephrodiutn (Polystichum) 

 spinulosum (true). 



" 2. Finely divided, or wood form : Nephrodiura (Polystichum) dila- 

 tatum. 



"3. Simplified or bog form: N. cristatum. 



"3rd remark. — That excellent judge of German ferns, Professor A. 

 Braun, of Freiburg, and after him Doll, in his valuable ' Rheinische 

 Flora' (pp. 17 — 18), discriminate the following forms of this variable 

 species : — 



" a. elevatum, A. Br. — Rhizome prostrate, rather thin ; stipes long, 

 erect ; axis nearly naked ; frond small, barren towards the base, 

 doubly pinnate and pinnatifid; the lower pinnae distant, nearly as long 

 as the following ; pinnules short, with approximate, serrate, sharp- 

 pointed, acuminate segments, whose teeth are somewhat curved up- 



