Probable Base Number for Genus x = 10
G. pinnatifida 2n= 30 I ref Rozenblum et al. 1988 (listed as Eupatorium tanacetifolium)
References
Rozenblum, E., S. Maldonado, and C. E. Waisman. 1988. Apomixis in Eupatorium tanacetifolium (Compositae). American Journal of Botany 75: 311-322
Watanabe, K., T. Yahara, G. Hashimoto, Y. Nagatani, A. Soejima, T. Kawahara, and M. Nakazawa. 2007.
Chromosome numbers and karyotypes in Asteraceae. Annals of the Missouri Botanical Garden 94: 643-654.