Cryptorhopalum

Cryptorhopalum is a genus of fungi in the family Lecanoraceae. The genus was described in 1982 by G. M. H. Peršič. Species within this genus are typically crustose lichens, meaning they form a tightly adhering crust on their substrate. Their thallus, or vegetative body, is often thin and can be a variety of colors, frequently gray, greenish, or sometimes even somewhat yellowish. The reproductive structures, apothecia, are usually lecanorine, a type of apothecium characterized by a thalline margin, which is a ring of fungal tissue derived from the thallus.

The distribution of Cryptorhopalum species is generally considered to be Holarctic, with some species found in North America and Eurasia. They typically grow on bark or wood, often on trees in woodland or forest environments. Identification of Cryptorhopalum species relies on a combination of morphological characteristics, such as the color and texture of the thallus, the shape and color of the apothecia, and the presence or absence of specific chemical compounds that can be detected using thin-layer chromatography. Further research is ongoing to fully understand the diversity and ecological roles of this fungal genus.