Magee, Anthony Richard, JAMES S. BOATWRIGHT, and LADISLAV MUCINA. 2014. “Four New Species of <em>Ursinia</Em> (Asteraceae, Anthemideae) from South Africa, With an Updated Key to the Genus in Namaqualand”. Phytotaxa 177 (3):137–145. https://doi.org/10.11646/phytotaxa.177.3.1.