This species is characterized by its herbaceous annual habit, leaves in a basal rosette, inflorescences with one to several glomerulate heads, white to blue corollas 2-3 mm long, and capsules 1--2 mm long. It is variable, and Steyermark (1963) recognized several varieties based on density and distribution of pubescence; all but two varieties were later synonymized by Taylor et al. (2004: 696), as discussed there.

• Taylor, C. M., J. A. Steyermark, P. G. Delprete, A. Vincentini, R. Cortés-Ballén, D. C. Zappi, C. H. Persson, C. B. Costa & E. Anunciação. 2004. Rubiaceae. 8: 497–847. In J. A. Steyermark, P. E. Berry & B. K. Holst (eds.) Fl. Venez. Guayana. Missouri Botanical Garden Press, St. Louis.