2d. When P. Thelyp. grows old, the under side of the leaf is totally covered with the confluent fructifications, and the edges of the pinnulæ are reflexed or contracted. In P. Oreopt. the fructifications are always on the margins, both in a young and old state, and never run into one another; the lobes oval and plain.
3d. The size of this plant is four times as large as that of P. Thelypteris, and the latter always grows in boggy places; whereas P. Oreopt. grows in dry woods, moors, and on hills, very rarely near water.
Linnæus, in Flo. Suec. says of P. Thelypt. puncta minutissuna dispersa.
I know of no figure of P. Oreopteris. Mr. Bolton has given a small fig. t. 22, f. 2, which may be it; but as he has joined it with P. Thelypt. it is not worth notice[1].
I have found it both in England and Scotland, most plentifully in the latter.
How Mr. Lightfoot could mistake this fern, I cannot understand.
- ↑ Since the above was written, Mr. Bolton has, in a letter to Mr. Dickson, acknowledged his P. Thelypteris to be the P. Oreopteris. His Acrostichum Thelypteris (Fil. Brit. t. 43.) is the true Polypodium Thelypteris of Linnæus.
