In addition to these, many exotic lichens, belonging especially to Parmelia and Sticta (e.g.
The chief of those employed for one or other, and in some cases for several, of these purposes were Cladonia pyxidata, Usnea barbata, Ramalina farinacea, Evernia prunastri, Cetraria islandica, Sticta pulmonaria, Parmelia saxatilis, Xanthoria parietina and Pertusaria amara.
Yellow dyes, again, are derived from Chlorea vulpina, Platysma juniperinum, Parmelia caperata and P. conspersa, Physcia jlavicans, Ph.
At one time also some species were used in the arts for supplying a gum as a substitute for gum-arabic. These were chiefly Ramalina fraxinea, Evernia prunastri and Parmelia physodes, all of which contain a considerable proportion of gummy matter (of a much inferior quality, however, to gum-arabic), and were employed in the process of calico-printing and in the making of parchment and cardboard.