H. guevarae n=10 ref Powell & King 1969 (as Eupatorium guevarii)

H. macrophyllum n=10; 2n=20 ref King et al. 1976; Powell & King 1969; Robinson et al. 1989; Watanabe et al. 1995

H. sericeum n=10 ref Powell & King 1969 (as Eupatorium sericeum)

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.

Powell, A. M. and R. M. King. 1969. Chromosome numbers in the Compositae: Colombian species. American Journal of Botany 56: 116-121.

Robinson, H., A. M. Powell, G. D. Carr, R. M. King, and J. F. Weedin. 1989. Chromosome numbers in Compositae, XVI: Eupatorieae II. Annals of the Missouri Botanical Garden 76: 1004-1011.

Watanabe, K., R. M. King, T. Yahara, M. Ito, J. Yokoyama, T. Suzuki, and D. J. Crawford. 1995. Chromosomal cytology and evolution in Eupatorieae (Asteraceae). Annals of the Missouri Botanical Garden 82: 581-592.