Potent roots on the move:calumba and abutua as African, imperial, and global medicines, c. 1700s–1900s

Abstract Calumba (Jateorhiza calumba / J. palmata) and abutua (Cissampelos pareira) are multi-purpose medicinal plants, whose roots have been used in Eastern, Southern, and West-Central Africa for a considerable time. In the early modern era, the Portuguese adapted the roots, which became commercially traded in the Portuguese empire across the Indian and Atlantic Oceans. By the early nineteenth century, the roots were recognized also by the British and North American pharmacopoeias, but there was confusion and secrecy surrounding their origins and quality. Engaging with recent historiography about African and imperial plant medicines, we demonstrate that calumba and abutua had long, dynamic, and mobile continuities on the continent—first in Portuguese imperial settings and then in appropriation by British botanists and colonial officials in East Africa. Exploring African agency in the making of knowledge about calumba and abutua is problematic, however. While in the longue durée, calumba and abutua maintained their value and meanings within Africa, in certain moments, these plants became objects of scientific curiosity and heightened commercial interest in the West