''Verrucaria nigrescens'' is a widespread species of crustose lichen in the family

Verrucariaceae The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose ( ...

. It was first formally described as a new species by

Christiaan Hendrik Persoon Christiaan Hendrik Persoon (1 February 1761 – 16 November 1836) was a German mycologist who made additions to Linnaeus' mushroom taxonomy. Early life Persoon was born in South Africa at the Cape of Good Hope, the third child of an immig ...

in 1795. The lichen produces a very dark brown thallus that grows on rocks; the medulla is black. There are black perithecia that resemble buried dots, and which measure 0.15–0.3 mm in diameter. Ascospores measure 14–24 by 7–11

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

References

nigrescens Lichen species Lichens described in 1795 Lichens of Europe Lichens of North America Taxa named by Christiaan Hendrik Persoon {{Eurotiomycetes-stub

See also

References