2 Rhodora [JANUARY 
smaller scales on the stipe and especially on the back of the frond 
from which they are often essentially wanting. Careful examination 
of these scales indicates no specific difference, nor do characters appear 
in the indusia and spores. The two plants seem, then, to be an arctic 
and a temperate eastern American and eastern Asiatic variation of 
one specific type. 
In determining which of the two is the nomenclatorial type of the 
species we fortunately are aided by good descriptions. Linnaeus 
founded his Polypodium fragrans upon the Siberian Dryopteris Rubum 
Idaeum spirans of Amman. The Linnean account! is as follows: 
32 PoLyrobrum frondibus sub-bipinnatis lanceolatis: foliolis fragrans. 
confertis: lobis obtusis serratis stipite paleaceo. 
Dryopteris Rubum Idaeum [misprinted by Linnaeus rubrum idaeum] 
spirans. Amm. ruth. 251. 
Habitat in Siberia. 
Habitus P. F. Maris, at longe minor. Foliola densius congesta, lobis 
lateralibus obtusis, profundius serratis. 
Amman gave a fuller description? though without any additional 
characters, but his paragraph explaining the name and the type 
locality is worth quoting: 
“Tenisae incolae, vt refert Gmelinus hanc plantam cereuisiae 
incoquunt, quae gratum inde Rubi Idaei odorem et saporem acquirit. 
Sicca etiam in conclaui asseruata totum conclaue odore suo implet. 
In Angarae et Selengae fluuiorum montosis prouenit. Tanquam 
efficacissimum antiscorbuticum Gmelino commendata fuit. ” 
The Angara rises to the northwest of the Baikal Mountains in 
Siberia and the Selenga enters Lake Baikal from the south. The 
typeregion was, then, the mountains of the Baikal region, and material 
from that area (“ad Baikalem") well matches the more arctic ex- 
treme. The description by Amman indicates this plant and the 
briefer one of Linnaeus with its “foliolis confertis" seems conclusive, 
that true Thelpteris fragrans is the more northern extreme. 
The southern extreme was clearly recognized by Hooker in 1862, 
when he described the typical Nephrodium fragrans, of * High arctic 
or subarctic regions," with fronds “destitute of scales above, while 
the wholeof the rest of the plant is richly palaceous with aureo-nitent 
scales," and set off as Var. "6, slender submembranaceous very 
sparsely scaly,” the plant of “the Caucasus" and of Wisconsin, 
1 L. Sp. Pl. ii. 1089 (1753). 
? Amman, Stirp. Rar. Imp. Ruth. 174 (1739). 
