

As other users highlighted, canola is a specific cultivar of rapeseed. The name is for Canadian oil, low acidity. It was originally a brand.
Wiktionary also lists “colza”, ultimately from Dutch koolzaad (cabbage seed). I never saw it in English, only in Portuguese (and even then it was an “ackshyually” moment).
In a lot of Indo-European languages you’re stopping right at 5, *pénkʷe. For example Greek (πέντε pénte) and Sanskrit (पञ्चन् páñcan).