Raphanus

1. Petals yellow to white but usually with conspicuous dark veins when fresh; mature fruit at most ca. 4 mm broad, strongly constricted with prominent corky partitions between the seeds (often with 4 or 5 seeds).

R. raphanistrum

1. Petals purple or sometimes white; mature fruit ca. 8–12 mm broad, not constricted, usually 2–3-seeded.

R. sativus

All species found in Raphanus

Raphanus raphanistrumWILD RADISH 
Raphanus sativusRADISH 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. June 27, 2017. http://michiganflora.net/genus.aspx?id=Raphanus.