Placomaronea fuegiana is a species of saxicolous (rock-dwelling), crustose lichen in the family Candelariaceae.

The type specimen was collected by the second author in Tierra del Fuego, Argentina, where it was found growing on sandstone.

As they mature, they may turn irregular in shape, with some areas slightly incised, reaching widths of up to 0.6 mm.

Initially flat, the disc eventually becomes convex, with a slightly darker yellow hue than the thallus and a smooth to somewhat coarse texture.

Pycnidia, the asexual fruiting structures, are sparse and can be spotted as orange, shallow indentations on the thallus.