Specimens of this species from Florida were originally identified as B. brevicornis (Deyrup, 2002; Deyrup et al., 2000), but is currently thought to belong to a different, possibly undescribed species (Deyrup, pers. comm.). MacGown provides the following description.
Workers of this particular species or form, are shiny dark brown, with pale yellowish-brown appendages. They lack erect hairs on the promesonotum, the occipital region of the head, and the femora. The head has moderate pubescence (in full face view); the dorsum of the alitrunk has sparse pubescence, but the sides lack pubescence and are very shiny; and the gaster has somewhat sparse pubescence. The eyes have about 6 facets in greatest diameter.
This species differs from other brown Brachymyrmex species (Brachymyrmex heeri - possible in the U.S., Brachymyrmex obscurior, and Brachymyrmex patagonicus) known or likely to occur in the U.S. in that it lacks erect hairs on the head, promesonotum and femora. An undescribed brown species known only from two queens collected from Arkansas (Lloyd Davis, pers. comm.) is unusual in that the queens are tiny, about the size of typical workers. All other known species present in this region are yellowish in color.