Hydropunctaria maura

Species of lichen

Hydropunctaria maura, still often called by the older name Verrucaria maura and commonly known as tar lichen, is a species of saxicolous (rock-dwelling), crustose lichen belonging to the family Verrucariaceae. A perennial species that does not experience seasonal variations, it is the type species of the genus Hydropunctaria. The medulla is a black basal layer that forms columns to the upper surface and isolates the algae into pockets near the upper surface. The black band formed by H. maura can often be seen at a distance as a marker of the high water point.

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