O. arizonica O. flavorubescens O. juniperina O. neobaltistanica Opeltia is a genus of lichen-forming fungi in the family Teloschistaceae.

[1] The genus was circumscribed in 2017 by lichenologists Sergey Kondratyuk and Laszlo Lőkös, with O. neobaltistanica assigned as the type species.

The genus name honours lichenologist Josef Poelt, "in recognition of his enormous contribution to lichenology".

[2] Opeltia occupies a distinct monophyletic branch within the Mikhtomia clade, a phylogenetically related group of taxa that also includes the genera Hanstrassia, Laundonia, and Oxneriopsis.

Its colouration varies, typically presenting in shades of whitish, dirty white, and occasional yellowish tones.