Amandinea (aka “Button Lichens”)
Description: Crustose lichens with thick, or– more frequently– very thin thalli. Tips of paraphyses enlarged & pigmented; asci variable in K/I reaction, but usually Bacidia-type.
Color: Brown to gray or almost white.
Photobiont: Green (Trebouxia).
Apothecia: Black, lecideine or lecanorine, usually with a persistent margin.
Hypothecium: Usually dark brown but sometimes pale.
Epihymenium: Brown to greenish
Spores: Brown, 2-celled, with uniformly thickened walls or with a thickened septum
Conidia: Very slender, long, & curved, mostly about 15 – 30 um long.
Chemistry: North American species without lichen substances.
Substrate: On rocks, bark, or wood, rarely soil.
Lookalikes: The long, arc-shaped conidia separate this genus from the closely related Buellia. Thallus & apothecial type vary from species to species, & even the spores are not uniform. In the coastal rock species A. coniops (British Columbia, Alaska, & Newfoundland), the septum separating the two cells is conspicously thickened; in most other species of Amandinea, it is not. This species also differs from the others in having a thick, areolate to verrucose, brown to gray-brown thallus & large spores, 12 – 18 x (6.3-) 8 – 9.5 um.
Bibliography: Lichens of North America, by Brodo, Sharnoff, & Sharnoff
Database Entry: Distance Everheart 12-26-13