The lichen is characterised by its yellow medulla, soralia on the margins on the lobes that make up the thallus, and the presence of the chemical lichexanthone in the cortex.

The lobes that comprise the thallus are 0.3–1.5 mm (0.01–0.06 in) wide, somewhat tightly apressed to the substrate and are more or less flat but often somewhat concave near the tips.

[10] Apothecia (reproductive structures) are common in tropical and subtropical specimens; they measure 0.3–1.5 mm (0.01–0.06 in) wide and have an indistinct internal stipe.

[10] It has been reported from Africa (Ethiopia, Uganda, Kenya, Tanzania, the Seychelles, Rwanda and Angola),[12] throughout Asia (including China),[13] Australia,[8] New Zealand,[14] In the eastern United States, its geographical range covers subtropical to more temperate regions, including the states of New York, Illinois, and Ohio to Florida, Louisiana, and Texas.

Pyxine subcinerea has been recorded growing on hornbeam, hickory, hibiscus, juniper, sweetgum, magnolia, oak, locust, elm, and the genus Prunus.

It tends to prefer low elevations, and occurs hardwood-pine forests as well as more open areas including farms, glades, and gardens.

It bioaccumulates toxic heavy metals that it acquires from the air and retains the pollutants in the thallus, which can then be sampled and assayed to determine their concentration.