364 Dr. HookEr’s Account of a 
With regard to pubescence, this species appears as liable to 
variation as the following one is known to be. | 
6. D. hirta. 
A very few specimens of this plant exist in the collection, 
and these belong to what I have considered as a fourth variety 
of D. hirta in my account of the plants of Captain Parry's 
second Voyage: as **1—3 pollicaris, foliis integerrimis, scapo 
gracili aphyllo." 
Some or other of the numerous varieties of this species are 
found in the alpine countries of the north of Europe and 
America ; and if the plant be, as I suspect, the R. nivalis of 
De Candolle, it is also a native of the mountains of Switzer- 
land, Savoy and Dauphiny. 
7. D. muricella. 
This quite agrees with the species so denominated by Wah- 
lenberg, in the nature of its pubescence: but two out of five 
stalks are furnished with a leaf; whereas Wahlenberg defines 
the D. muricella as having a ** scapus semper nudus." I am 
here more confirmed in an opinion, that I have elsewhere ex- 
pressed, that this is but a densely pubescent variety of D. hirta. 
The germens and silicules are stellato-pubescent. 
Whether a variety or a species, this plant exists on the alps 
of Switzerland, as well as those of Lapland, Norway and Si- 
beria. Dr. Richardson found itin Arctic America; Mr. Jame- 
son on the west coast of Greenland, and Captain Parry in the 
Strait of the Fury and Hecla. | 
De Candolle has placed the D. muricella in his division of 
the genus Chrysodraba; whereas the inflorescence is con- 
stantly white. Perhaps the D. tomentosa of that author might 
safely be referred hither. 
8. D. in- 
