The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
Native; European Southern-temperate plant. It was formerly scattered through England, Wales and Ireland, in the Isles of Scilly and on the Channel Islands, but has now declined very markedly.
In Cornwall Pennyroyal has undergone a dramatic decline. It has been recorded from 55 1km squares in total, including a former site on the Isles of Scilly. The remaining sites are at Penhale (SW61), Lowland Point (SW71), St. Loy (SW42), Luxulyan (SX05) and Pensilva (SX26), though some of these may be introduced plants.
Habitat & Ecology
Pennyroyal is a native perennial plant that grows in wet places on sandy soil, in poached and grazed pond margins, along winter-wet tracks and in ruts in old pastures.
Lack of disturbance and the surfacing of tracks.
Some disturbance of the ground by poaching, combined with heavy grazing by cattle or horses appears to be essential for its survival.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.