Redingeria develops a smooth, pale grey to yellow-olive crust (
thallus) seated directly on the bark and lacking a true . Its elongate, often slightly curved are 1–4 mm long, bordered by thick, charcoal-black () walls so the script-like slits stand out sharply against the thallus. A colourless to pale brown lines the interior, while the
hymenium is distinctly with minute oil droplets that give a cloudy aspect under the microscope. The thin-walled,
Graphis-type
asci hold eight hyaline
ascospores that become markedly —partitioned by numerous transverse and a few longitudinal
septa—yet remain iodine-negative (I–) and typically measure 30–70 × 8–15 μm.
Secondary chemistry is moderate: many species produce
stictic acid or
norstictic acid, occasionally accompanied by trace
protocetraric-series
depsidones that tint the yellow-brown. The mix of fully carbonised lirellae, a clearly inspersed hymenium and large, I– muriform spores distinguishes
Redingeria from superficially similar script lichens.
Glyphis and
Hemithecium share black margins but lack hymenial inspersion;
Acanthothecis and
Anomomorpha possess (spiny) and often iodine-positive elements; whereas
Kalbographa is set apart by its bright orange anthraquinone . ==Ecology==