This species is characterized by its medium-sized habit, its well developed flat ovate stipules with lacerate or erose glandular margins, its petiolate elliptic leaves without domatia, its pedunculate cymose inflorescences with the axes paired, its medium-sized flowers that are subsessile in several small groups and have a reduced calyx limb, its corollas with the tubes 4-7 mm long and lobes about as long as the tube and with well developed horns or rounded projects, and its rather small purple to purple-black fruits 8 x 5-7 mm. The axes of the inflorescences expand as the fruits develop.
Zappi (2000) circumscribed Rudgea verticillata rather broadly, and included Rudgea amazonica within her circumscription. However here Rudgea verticillata is circumscribed more narrowly, following the taxonomy of Standley (1936), and Rudgea amazonica is recognized. Rudgea verticillata is here considered to differ from Rudgea amazonica it is somewhat larger often broader leaves that often gray or blackened, verticillate inflorescence axes, more robust corollas, and larger fruits, to 22 x 13 mm. Some specimens of Rudgea verticillata and Rudgea amazonica are difficult to identify with confidence and may be misidentified.