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XIX. Offérvations on Polypodium Oreopteris, accompanied with a 
Specimen from Scotland. By Mr. J. Dickfon, Fellow of the Linnean 
Society. 
Read Fanuary 5, 1790. 
HIS ‘plant has been miftaken by all our Englifh botanifts. 
By fome it has been confounded with P. Thelypteris, by 
others with P. Filix mas; but it is very diftinét from both. Doody, 
Dillenius, Ray, Hudfon, Lightfoot, Bolton, &c. have all fallen 
into the fame error. For a full account of this plant I beg leave to 
refer to Vogler, who has written an entire differtation upon it, and 
calls it P. montanum. Wildenow gives it the fame name. Ehrhart 
in his Plant. Crypt. Decas 3, No. 22, has publifhed it by that of 
. P. Oreopteris, which we prefer; as the name of P. montanum has 
been given to another fpecies by Allioni. My opinion refpedting | 
this fern is fupported by that of Sir Jofeph Banks and Mr. Dry- 
ander, as well as of Dr. Smith and Mr. Jacquin ; and, as the dií- 
fertation above alluded to may not be in every body's hands, | fhail 
mention fome of the moft remarkable particulars in which this plant 
differs from P. Thelypteris. 
Ift. P. Thelypt. has a fmall creeping root, of which fee a good 
figure in Schmeidel's Icones Plant. t. xi. P. Oreopteris has a large 
{caly root, wrapped and tied together with {mall ftrong fibres which 
cannot be feparated without difficulty. 
2d. When 
