Probable Base Number for Genus x = 10
C. hebebotryium n=10 ref cf BLT 1997
C. hospitalis n=ca 10 ref King et al. 1976
C. morifolia n=10 ref Turner et al. 1962; King et al. 1976; Sundberg et al. 1986
C. quadrangularis n=10 ref Turner et al. 1962
C. sexangularis n=10 ref King et al. 1976
References
Grant, W. F. 1953. A cytotaxonomic study in the genus Eupatorium. American Journal of Botany 40: 729-742.
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.
Turner, B. L., A. M. Powell, and R. M. King. 1962. Chromosome numbers in the Compositae VI. Additional Mexican and Guatemalan Species. Rhodora 64: 251-271.
BLT 1997, Turner, B. L. 1997. The Comps of Mexico. Eupatorieae. Phytologia Memoirs Vol. 11.