Floret of cauliflower, Brassica oleracea

Scanning electron micrograph of a floret of a cauliflower, Brassica oleracea var. botrytis.The picture is a close view of part of the curd of a cauliflower; the frame is 3mm wide. B. oleracea has been bred to produce a variety of green vegetables, including cabbages, kales, kohlrabi and brussels sprouts. Each emphasises a particular feature of the species; the leaves, stems, side shoots, and in the case of cauliflower, the flowers. A cauliflower is an enlarged terminal bud at an early stage of flower development. In this picture, the flower buds are brown, borne on short stems (green). The youngest buds are in the centre of the frame. B. oleracea, a perennial cabbage, is native to coasts of NW Europe and the Mediterranean, in cultivation for >2500 years. Cauliflowers probably first appeared in the Middle Ages. Cauliflower is a good source of dietary fibre, Vitamin C and potassium, Creditline:DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY