Brassicaceae greens, Savoy, kohlrabi, and gai lan ("Brassica oleracea"), turnip, napa cabbage, bomdong, bok choy and rapini ("Brassica rapa"), rocket salad/arugula ("Eruca sativa"), garden cress ("Lepidium sativum"), watercress ("Nasturtium officinale") and radish ("Raphanus") and a few spices like horseradish ("Armoracia rusticana"), "Brassica", wasabi ("Eutrema japonicum"), white, Indian and black mustard ("Sinapis alba", "Brassica juncea" and "B. nigra" respectively). Vegetable oil is produced from the seeds of several species such as "Brassica napus" (rapeseed oil), perhaps providing the largest volume of vegetable oils of any species. Woad ("Isatis tinctoria") was used in the past to produce a blue textile dye (indigo), but
Vegetable oils as alternative energy than biodiesel. After there are production cars that can use straight vegetable oil and a standard type available at gas stations, consumers will probably choose straight vegetable oil to save money. So the transition to vegetable oil can happen gradually. Other methods, like nuclear power, fusion power, wind power and solar power, may provide cheaper electricity, so vegetable oil may only be used in peaking power plants and small power plants, as diesel is limited to today. There is at least one 5 MW power plant that runs on biodiesel. MAN B&W Diesel, Wärtsilä and other companies produce engines suitable