This widely grown annual ("radish") does occasionally escape, but it is probably not truly naturalized. There are colls. from FRAN (EKY) and WARR (WKY). R. sativus can be hard to distinguish from raphanistrum, and hybrids are possible (Y). Raphanus, Coincya and Eruca share the following character (FNA 7): petals usually white to yellowish (or sometimes pink), with dark brown to purplish veins; other Brassiceae lack distinctly colored veins. Experimental work on Raphanus has shown that "Wild radish responded to herbivory by producing new leaves with increased trichome density, but also with a systemic increase in the concentrations of secondary metabolites" (Dalin et al. 2008).