Sativa fails to persist because of selective grazing is discussed. Its low palatability to sheep was seen as an advantage in assisting its survival in extensive low-input grazing systems.
Dear, B., Li, G., Hayes, R., Hughes, S. J., Charman, N., & Ballard, R. A. (2007). Cullen australasicum (syn. Psoralea australasica): a review and some preliminary studies related to its potential as a low rainfall perennial pasture legume. Rangeland Journal, 29(2), 121-132. https://doi.org/10.1071/RJ06039