The males have dark wing covers, or elytra, with wide, blurred, light-colored side margins, and a pale yellow head shield, or pronotum, with a dark central mark shaped like a mushroom or a teardrop.

The larviform female resembles a colorful pink and yellow grub with no wings and very small elytra.

[6] The specific epithet is in honor of the naturalist Clement Samuel Brimley,[2] who mentioned the species in his 1938 Insects of North Carolina, although it was not named until John Wagener Green published Revision of the Nearctic species of "Photinus" in 1956.

A female responds with an answering flash from the entrance of her burrow or from a perch up to 15 cm (6 in) high on low vegetation.

[2][1] P. brimleyi has been recorded in the southeastern United States, including Tennessee, Kentucky, Alabama, Georgia, North Carolina, Oklahoma, and Arkansas.