Fruiting bodies are uncommon in this species; if present, they resemble small cups with a brown internal disc measuring 3–10 mm (0.1–0.4 in) in diameter.

The lichen was first formally described in 1942 as a new species by French lichenologist Maurice Bouly de Lesdain, as Parmelia graminicola.

The type specimens were collected by Brother Arsène Brouard, a Lasallian Catholic monk, in 1935 from two sites near Las Vegas, New Mexico, at an altitude of 1,900 m (6,200 ft).

[7] However, Bouly de Lesdain noted that the lichen was found growing on mosses and the spikemoss Selaginella.

[4] After the loss of the type material, the name Parmelia graminicola was often later relegated to synonymy with Punctelia subrudecta.

[9][10][11] In his original description of Parmelia graminicola, Bouly de Lesdain had noted its similarity to P. subrudecta.

[5] In 1980, William and Chicita Culberson reported their observations on the differences in the length of the conidia in populations of Parmelia hypoleucites collected from Arizona and Mexico.

[2] In 2001, after Robert Shaw Egan discovered that some of Brouard's collections had been rescued from being disposed at a local (New Mexico) landfill, the specimens were transferred to Arizona State University and curated.

[12] Adriano Spielmann and Marcelo Marcelli have noted that Punctelia graminicola has a broad species concept, as it include individuals both with and without lacinulae.

[6] The thallus undersurface ranges in color from pale tan to light to medium brown, with sparse, light-colored rhizines.

[13] The upper cortex is paraplenctenchymatous; this means that it is made of a type of tissue in which the hyphae are oriented in all directions, analogous to the parenchyma of plants.

It has been recorded growing on a wide variety of rocks: basalt, conglomerate, granite, limestone, rhyolite, sandstone, schist, and volcanic.

They suggest that the lichen "is primarily adapted to life on rock, extending substrate tolerance to bark only under the most favorable ecological conditions".