A common lichen found on rocks, used in Scotland to make a golden-brown or reddish-brown dye for staining wool for making tweed.
- Parmelia saxatilis (order Parmeliales) and other species
More example sentences
- At the top of the shore lichens or crotal grow on the rocks, and various species were boiled up with whole fleeces, water and the mordant human urine to give some of the unique hues associated with Harris Tweed.
- This is dark crottle or puffed shield lichen, Parmelia physodes.
- Of ancient origin, the crotal has remained unchanged over the years and is found throughout the world.
mid 18th century: from Scottish Gaelic and Irish crotal, crotan.
Definition of crottle in:
- The US English dictionary