Canola is a genetic variation of rapeseed developed in the 1970's by Canadian plant breeders specifically for its nutritional qualities, particularly its low level of saturated fat.  The word "rape" in rapeseed comes from the Latin word "rapum," meaning turnip.  The negative associations with the word "rape" in North America resulted in the more marketing-friendly name "Canola".   The word "canola" is derived from "Canadian oil, low acid".