About Enchylium tenax (Sw.) Gray
Enchylium tenax (Sw.) Gray is a species of lichen that has three common names: jelly lichen, black lichen, and desert lichen. It grows in Arctic and temperate regions across the Northern Hemisphere. It is very common in North America, and can also be found in Europe, Asia, and Africa. This lichen forms a thick black or dark green gelatinous thallus that varies in size, and is generally between 1 and 3 centimeters wide. It hosts Nostoc commune, a cyanobacterium that acts as its photosynthetic symbiont. It can reproduce either when fragments of its thallus break off, or through the production of isidia, soredia, and apothecia. It is tolerant of desiccation: it shrinks when dry and swells up when water is available. Enchylium tenax is terricolous, meaning it grows directly on the soil surface. It acts as an indicator of basic soils, and is often found on gypsum-rich and other calcareous soils. It is a common component of cryptobiotic soil crusts, particularly in the dry regions of the western United States. This species fixes nitrogen, which increases the nitrogen content of the soil it grows in.
