Verrucaria serpuloides

{{Short description|Species of lichen found in Antarctica}}

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| taxon = Verrucaria serpuloides

| authority = I.M.Lamb (1948)

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Verrucaria serpuloides is a species of saxicolous (rock-dwelling), crustose lichen belonging to the family Verrucariaceae. It is native to the Antarctic Peninsula. It is one of only two permanently submerged species of lichen, the other being Hydrothyria venosa, and the only one found permanently submerged in a marine environment.{{cite journal |last1=Ahmadjian |first1=V. |title=Lichens are more important than you think |journal=BioScience |date=1 March 1995 |volume=45 |issue=3 |page=1 |doi=10.1093/bioscience/45.3.124 |url=https://academic.oup.com/bioscience/article-abstract/45/3/124/252273?redirectedFrom=PDF |access-date=14 September 2021|url-access=subscription }} Collections of the species were first made in 1944 by Elke Mackenzie.{{cite journal |last1=Lamb |first1=I. Mackenzie |title=Further observations on Verrucaria serpuloides M. Lamb, the only known permanently submerged marine lichen |journal=Occasional Papers of the Farlow Herbarium of Cryptogamic Botany |year=1973 |issue=6 |pages=1–5 |jstor=41760455 |issn=0090-8754}}

The species has been discovered living up to {{convert|10|m|ft|abbr=on}} below mean high tide. It creates jet-black patches on the base of submerged rocks. It uses green algae as a symbiont.