It typically grows on rocks, old walls, and tree trunks, particularly favoring nutrient-enriched areas such as birds' perching stones, though it is sensitive to sulfur dioxide pollution.

[4] The genus name Diploicia derives from the Greek word diploos, meaning "two-fold" – a reference to its two-celled ascospores.

The thallus, which can range in color from white to very pale gray, is typically darker in the center and very white-pruinose on the marginal lobes.

[7] Like many lichens, D. canescens disperses primarily by means of symbiotic vegetative propagules; most are covered with extensive mats of soralia.

Apothecia are rare, but where they occur are black, lecideine (meaning that they have no thalline margin), and measure 0.3–1 mm in diameter.

[10] It occurs on rocks, old walls, and tree trunks,[11] favoring nutrient-enriched areas, such as birds' perching stones.

[12] Diploicia canescens contains various chemical compounds including depsidones (such as diploicin and scensidin), depsides (atranorin and chloroatranorin), phthalides (buellolide and canesolide), dechlorodiploicin, isofulgidin, and minor or trace amounts of dechloro-O-methyldiploicin and secalonic acids A, B, C.[4][13] Derivatives of diploicin have been shown, in vitro, to be active against bacterial species including Mycobacterium smegmatis, Corynebacterium diphtheriae (mitis), and M.