Romanesco broccoli, or Roman cauliflower, is an edible flower of the species Brassica oleracea, and a variant form of cauliflower.
Romanesco broccoli was first documented in Italy (as broccolo romanesco) in the sixteenth century.
It is sometimes called broccoflower, but that name is also applied to green-curded cauliflower cultivars. Romanesco broccoli resembles a cauliflower, but is of a light green color and the inflorescence (the bud) has an approximate self-similar character, with the branched meristems making a logarithmic spiral. In this sense the broccoli's shape approximates a natural fractal; each bud is composed of a series of smaller buds, all arranged in yet another logarithmic spiral. This self-similar pattern continues at several smaller levels.
The vegetable is rich in vitamin C, vitamin K, dietary fiber, and carotenoids.
The head of Romanesco broccoli is a visually striking example of an approximate fractal in nature. The pattern is only an approximate fractal since the pattern eventually terminates when the feature size becomes sufficiently small. In computer graphics, its pattern has been modeled as a recursive helical arrangement of cones. The number of spirals on the head of Romanesco broccoli is a Fibonacci number.