crottle

Noun

1. Any of various lichens gathered for dyeing, especially those of the genus Parmelia.
   • It was known and uſed as a dye-ſtuff in the Highlands of Scotland by the name of corkes or crottel, ſome hundred years ago. - 1791, John Sinclair, The Statistical Account of Scotland, volume 12, page 113:
   • Not that crotal and white was as humdrum as a simple definition of it as ‘brown and white’ implies. Crotal was the grey lichen which, over hundreds of years, had grown over the moorland rocks particularly - 1982, Finlay...
   • Parmelia omphalodes and P. saxitilis, the “crottles” used traditionally in Britain and Ireland, are sub-alpine lichens in North America. - 1993, Karen Leigh Casselman, Craft of the Dyer: Colour from Plants and Lichens,...