Probable Base Number for Genus x = 16
E. nelsonii n=16 ref Sundberg et al. 1986
References
King, R. M., D. W. Kyhos, A. M. Powell, P. H. Raven, and H. Robinson. 1976. Chromosome numbers in Compositae. XIII. Eupatorieae.
Annals of the Missouri Botanical Garden 63: 862-888.
Sundberg, S., C. P. Cowan, and B. L. Turner. 1986. Chromosome counts of Latin American Compositae. American Journal of Botany 73: 33-38.