Arthonia stevensoniana

By Laura Briscoe

May 27 2020

Arthonia etymology unknown

stevensoniana from Stevenson, honoring Robert Louis Stevenson, author of Treasure Island, and the Latin suffix -iana, meaning belonging to.

At first glance you might only notice the beautiful red-orange fungus in this photo, Haematomma accolens. But look a little closer and you will see several of those discs blighted out by a black spot. This is a parasitic species of lichen, Arthonia stevensoniana, a parasite that takes over its host. It leaves the host darkened, turning the bright red apothecia into a 'black spot,' much like spot used by the pirates in Treasure Island as a threat of harm or death.

A Closer Look

Lendemer, J.C., Harris, R.C., and A.M. Ruiz. 2016. A Review of the Lichens of the Dare Regional Biodiversity Hotspot in the Mid-Atlantic Coastal Plain of North Carolina, Eastern North America. Castanea: 81(1): 1-77.