Little-Known Facts About Lichens

	Lichens are the dominant terrestrial vegetation on about 8% of the Larth's surface. In the Antarctic there are 2 species of vascular plants and 350 species of lichens.
	During the Middle Ages, the Doctrine of Signatures proposed that plants resembling a human body part could be used to treat disorders pertaining to that body part. Because of ins resemblance to lung tissue, lungwort (Lobaria pulmonaria) was used as a remedy for tuberculosis and other diseases of the lungs. Peltigera canina was thought to ward off dog bites or alleviate symptoms of rabies.
	Manna from "heaven" is thought to be masses of Lecanora esculenta or L. affinis that have broken loose and accumulated in wind-blown piles, 5 to 6 inches deep. Today L. esculenta is important forage for sheep in the Middle East.
	No mordant is needed to set the color in lichen dyes for wool and silk. During the Middle Ages, the shellfish Murex and the lichens Roccella tinctoria and R mantagnel were the source of orchil dyes including the exclusive royal purple that was worn by the privileged few in the church and royalty. Litmus paper is made from these same lichens. It is pink in acidic media and blue in alkaline media.
	The Scots and Laplanders are fond of the warm browns from Parmelia omphalodes and P. saxatilis Harris tweeds are also made from these lichens, which give the wool a characteristic aroma. Lichen dyes were very important before the synthetic dyes were developed. Lichenologists are happy that lichen dyes are not commonly used now since a population of lichens representing many years growth can be wiped out.
	Lichens are the beginning of the food chain in higher latitudes and altitudes or anywhere where the soil or climate doesn't support the growth of grasses. These lichens are essential forage for reindeer and caribou.
	Lichens stabilize soils, prevent erosion, and help with water retention. Lichens are the pioneering species on bare soil or rocks. They hold moisture and add organic matter so other species can gain a foothold.
	Lichens are used in the manufacture of perfumes. Pseudevernia furfuracea is often used.
	Some Cladinas are used as miniature shrubbery for model train hobbyists. The preferred species is Cladina stellaris.
	Lichens are used as indicators of air quality. The British Isles and Northern Europe have been mapped and zoned for the various lichens depending on their ability to withstand air pollution. This information will serve as a benchmark for comparison for future centuries. Because the ratio of chlorophyll to plant mass is much lower for lichens than for other photosynthetic organisms, they are more susceptible to degradation of chlorophyll. They serve as miners' canaries for other species.
	Historically lichens have been lumped with mosses since they are often found growing together. It wasn't until mid-nineteenth century that the dual nature of lichens was suggested.
	Lichens are very slow growing, averaging 1 to 10 mm per year. Rhizocarpon geographicum grows about 1 cm in 100 years. These growth rates have been used for dating exposed rock surfaces and rock constructions.
	Lichens obtain nutrients directly through their thallus/body. After above- ground nuclear testing and the Chernobyl accident, the Eskimos and Laplanders were told not to eat reindeer or caribou since they feed on reindeer lichens and would assimilated radioactive materials. These populations are dependent on these herbivores for their meat.
	The fungi in lichens, or lichenized fungi are highly specialized in their relationship with algae or cyanobacteria as a means of getting energy. Non­lichenized fungi live on decaying organic matter (saprophytes) or parasitize living organisms.
	Rock tripe, Umbilicaria esculenta, was served as a delicacy in Japan. Other umbilicate lichens have been known to sustain members of Arctic expeditions, although the food value is questionable.
	Lichens were used to stuff the body cavities of Egyptian mummies.