Myriospora smaragdula  

Thallus very polymorphic, typically yellow, pale fawn-brown, rarely bright yellow-green, often of a waxy appearance, either of widely scattered, rounded, peltate, low convex, slightly swollen areoles 1-1.5 mm in diam., or contiguous convex areoles forming a well-developed, continuous crust; surface smooth, warted or concentrically ridged; photobiont layer continuous.
Anamorph: no information available.
Teleomorph: ascomata apothecia, (1-) 3-7 (-12) per areole. Thalline margin absent to well-developed, black and friable. Disc dark or black-brown, typically minute, 200-300 µm diam., plane, smooth, occasionally widening to ca 700 µm diam., rarely sessile and becoming umbonate. Hymenium 60-280 μm high. Interascal tissue of mostly unbranched narrow paraphyses 1-1.5 μm diam., 1.5-3 μm at the base. Asci cylindric-clavate, with an enormous apical dome, multispored. Ascospores 2-5 × 1-2 μm, ellipsoidal, hyaline, aseptate, smooth, without an epispore or gelatinous sheath.
Chemistry: thallus C–, K+ red, KC+ red, Pd+ yellow (norstictic acid in the medulla and photobiont layer, sometimes in small amount), rarely K– or KC–.