Species: Lecidella elaeochroma f. elaeochromaGrowth type crustose. Photos: On Ash and Sycamore. SW Ireland.
Very variable. Smooth or slightly granular, light-grey to yellowish-grey thallus surrounded by black prothallus. Often forms large mosaics. Apothecia with black discs, initially concave then convex with broad margins that become excluded. Ascus 8-spored, spores simple, thick-walled, 10-17 x 6-9 Ám. Microscope photos below.
L. elaeochroma f. soralifera has greenish-yellow soralia.
A pioneer species, common on smooth-barked trees and fences.
K+ yellow, C+ orange (usually), KC+ yellow, P-, UV+ orange. Reactions can be faint.
Similar: Amandinea punctata. Chemical reactions negative. Buellia disciformis. K+ bright yellow, C-. Spores 1-septate