Pogonomyrmex angustus-group

Workers of the P. angustus group can be recognized by the following characters: (1) small size (HW < 1.20 mm and ML < 1.70 mm), (2) poorly developed psammophore that consists of short to medium-length hairs scattered over ventral surface of head, (3) superior and inferior propodeal spines well developed, usually similar in length, (4) posterior face of petiole and dorsum of postpetiole smooth and shining or strongly granulate, rugae lacking, (5) dorsal surface of mesosoma smooth and shiny, lacking rugae; if rugae present, then interrugae strongly granulate-punctate, and (6) anteroventral margin of peduncle with small acuminate spine. Queens are: (1) small (HW < 1.25 mm and ML < 2.00 mm), (2) have a poorly developed psammophore, and (3) anteroventral margin of peduncle with small acuminate spine. Males are: (1) small (HW < 1.15 mm and ML < 2.00 mm), (2) funicular segments have very dense, short, suberect hairs, and (3) anteroventral margin of peduncle with small acuminate spine.