Carl Linnaeus, The Lapland Journey, translated by Peter Graves (Edinburgh: Lockharton Press, 1995), p. 196.

Northern Husbandry, 06/10/1732, ¶1156:

The womenfolk use ‘Lichenoides saxatile’ [lichen] for dyeing.8 It produces a brown colour, a colour resembling human excrement. They boil the moss in water without alum, though some add a little orellin. They only use it to dye woollen homespun or stockings.