54 FLORA ORCADENSIS. 
302. M. ARVENSIS (Linn.), Corn Mint. Rare. 
It is given in R. Heddle’s list of plants as local. I 
have never met with it where it seemed to be native. 
303. M. prpERITA (Linn.), Peppermint. Rare. 
In September 1911 I found a considerable patch 
in a marsh near the source of the burn passing the 
Public School, St. Andrews. The burn leading into 
this marsh passes, I think, only one small croft oc- 
cupied by Pratt. It is not likely to have come from 
there. I am inclined to consider it native, especially 
in view of subsequent finds. Also found in East Ross, 
Banff and Aberdeen, but not considered native in 
last two. Found several in burn above Quoykay, St. 
Andrews, in 1912. 
Genus CXLVIIL—NEPETA (Linn.) 
304. N. HEDERACEA (Trev.), Ground Ivy. Not 
common. 
This plant is established in several places, but. 
always seems to be a garden escape. Used formerly 
for medicinal purposes. 
Genus CXLIX.—THYMUS (Linn.), 7hyme. 
305. T. S—ERPYLLUM (Linn.) 
This is a common plant in the West Mainland. I 
have never seen it in Deerness, nor, | think, in any 
other part of the East Mainland. 
Genus CL.—PRUNELLA (Linn.) 
306. P. vuLtGARisS (Linn.), Self-heal. Commen. 
I have sometimes met with a white variety, with 
