Lecidea tessellata has a chalky white to grey, cracked and areolate
thallus. Its
apothecia are black, subimmersed, appressed to adnate and range from 0.5 to 1.8 (–2.0) mm in diameter. The apothecial is smooth, initially rounded in young apothecia, but becomes convex and irregular in mature ones, sometimes with a thin white pruinose layer. The is brownish-green to blackish-green and the is colorless, measuring 40–60
μm in height. The is pale brown and measures 30–40 μm in height, while the is blackish-green externally and colorless internally. The are clavate and measure 30–50 by 8–14 μm, and the ascospores are
ellipsoid and measure 7–9 by 5–6 μm.
Lecidea tessellata contains confluentic acid, a
lichen product that can be detected using
thin-layer chromatography. Both the thallus and
medulla of the lichen have negative reactions with standard chemical
spot tests (K−, C−, PD−).
Lecidea oreophila, found in the mountains of California's
Sierra Nevada, is similar in appearance to
L. tessellata, but it has a dark hypothecium and produces 2′-
O-methylmicrophyllinic acid as the primary lichen product, with or without accessory confluentic acid. ==Habitat and distribution==