The
thallus of
Lecidea coriacea is thin and mostly endosubstratal, appearing whitish grey or pale greenish grey in fresh samples. Occasionally, it can be episubstratal in part, with a continuous or fragmented surface that sometimes has soredioid granules and yellowish pigmentation. The is . The
ascomata are numerous, rounded to irregular, and often tuberculate. They measure 0.2–0.6 mm in diameter, with some reaching up to 0.8 mm. The is pale yellowish brown to dark brown, flat to strongly convex, and lacks . The margin is distinct, thin, and slightly darker than the disc. The is about 170–190
μm high, pale yellow, and reacts with
potassium hydroxide solution (K) to produce a golden yellow colour. The
hymenium is colourless and measures approximately 110–140 μm in height.
Asci contain 12–16 colourless, simple s, which measure 3.9–4.6 by 7.3–9.1 μm.
Pycnidia are rare and roughly spherical (), with
conidia that are threadlike (). The thallus of the lichen does not react with any standard chemical
spot test reagents, indicating the lack of
secondary metabolites. The golden yellow colour resulting from the reaction of K with the hypothecium is due to the compound secalonic acid A. ==Habitat and distribution==