The margin may appear black or masked by grayish remnants of necrotic thalline material, forming a thin and usually persistent boundary, occasionally excluded as they mature.

The disc is characterized by a black, epruinose surface, typically flat but occasionally developing a slight convexity over time.

Outer excipular hyphae are arranged parallelly, moderately swollen (textura oblita), and heavily carbonized, displaying a range of brown shades and aeruginose pigments.

The ascospores soon become brown, 1-septate, oblong to ellipsoid, usually not constricted, with obtuse ends, and not curved, measuring (8-)8.7-[9.9]-11.1(-13) x (4.5-)4.8-[5.5]-6.1(-7) μm.

[3] Buellia stellulata, an epilithic lichen, thrives on siliceous rock surfaces (typically HCl-) and is commonly found in coastal regions.