The
thallus of
Graphis appendiculata grows on bark, typically across and about 50–100
μm thick. It forms a continuous crust with a smooth surface that is white to pale gray, and it contains a photobiont (
Trentepohlia-type alga). In cross-section, the thallus has a upper , an irregular , and conspicuous clusters of crystals. The lirellae are (wavy) and irregularly branched, often arranged in radiating lines. They range from immersed to (breaking through the thallus surface) and are typically 3–7 mm long, about 0.1–0.2 mm wide (becoming abruptly thinner at the ends), and about 0.15–0.2 mm high. The is concealed. The (the "lips" bordering the slit) are finely but distinctly grooved () and appear black to dark gray, and the is white to pale gray. Microscopically, the is and apically (blackened), while the lateral and basal parts are orange-brown; the
hymenium is clear. The
asci contain eight oblong
ascospores that are 9–13-
septate and about 40–60 × 9–13 μm; The spores are I+ (
staining violet-blue in an iodine test). No
lichen substances were detected by
thin-layer chromatography. ==Habitat and distribution==