The Brussels sprout is a member of the Gemmifera cultivar group of cabbages, grown for its edible buds.
Brussels sprouts (cultivar unknown)
Brussels sprouts prepared for cooking in a wood-fired pizza oven
Brussels sprouts at the beginning of their formation, in Wattrelos (Nord), France
Brussels sprouts ready for harvest
Cabbage, comprising several cultivars of Brassica oleracea, is a leafy green, red (purple), or white biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage, and belongs to the "cole crops" or brassicas, meaning it is closely related to broccoli and cauliflower ; Brussels sprouts ; and Savoy cabbage.
A savoy cabbage and a cross section
The cabbage inflorescence, which appears in the plant's second year of growth, features white or yellow flowers, each with four perpendicularly arranged petals.
Cabbage
Harvesting cabbage, Tacuinum Sanitatis, 15th century