Found in Africa and South America, it was formally described as a new species by Norwegian lichenologist Bernt Lynge in 1914, as Parmelia riograndensis.

The type specimen was collected in 1892 from Porto Alegre Municipality in Rio Grande do Sul State (Brazil) by Swedish lichenologist Gustav Malme.

[2] The lichen has a greenish-gray thallus measuring 6–8.5 cm (2.4–3.3 in) wide, and which is closely attached (adnate) to its substrate (tree bark).

The lobes that comprise the thallus are crowded, sometimes overlapping, and measure 1.5–6 mm (0.06–0.24 in) wide.

Ascospores have an ellipsoid to ovoid shape with one or two slightly spiky tips, and measure 20.0–26.5 by 12.5–16.0 μm.