Port-hole Lichen

Menegazzia terebrata has a glossy blue-grey thallus and a black, wrinkled undersurface. This species does not have any rhizines on the undersurface. The medulla is white. Asci contain eight single-celled ascospores, like most species of Ascomycota. The spores are amyloid positive. The outside edges are different shades of brown. This species is distinguished by small holes in the upper thallus. Apothecia are rarely seen on this species so they mostly reproduce asexually. The lobes of this lichen are rounded and almost tube-like, with soredia on the lobe tips. The holes in its upper surface give the lichen many of its common names, including treeflute lichen, honeycomb lichen, and keyhole lichen. A potassium hydroxide test will produce K+ yellow results on the surface and medulla of this lichen.

Menegazzia terebrata grows on acidic substrates, including trees and rock. It prefers acidic species of tree, including alder, beech, and northern white cedar. It also prefers to grow on more acidic siliceous and siliciferous rock. It is most common in northern wet-mesic forests. It can be an indicator of an old growth forest. This species sometimes grows with moss, and often the moss grows between the lobes of lichen. It is often found growing on coastlines near the ocean. Menegazzia terebrata was found to be an indicator species of clean air in Western Oregon and Washington. In Nepal, Menegazzia terebrata has been reported from 1,300 to 4,000 m elevation in a compilation of published records.