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 carbon dioxide (CO) out of the Earth's atmosphere to make vegetable oil. The same CO is then put back after it is burned in an engine. Thus vegetable oil does not increase the CO in the atmosphere, and does not directly contribute to the problem of greenhouse gas. It is really a way of catching and storing solar energy; it is a renewable energy. However, as with other "renewable" energy sources, there may be a (relatively small) carbon footprint associated with production or distribution of vegetable oil. Vegetable oil is far less toxic than other fuels such as gasoline, petroleum-based