Kale is a vegetable with green or purple leaves. It is also called borecole. It is in the group of vegetables called Brassica oleracea or wild cabbage. It is cruciferous because of the shape of its flowers.
A plant that would have been first cultivated in the Mediterranean area, it was called in these times cabbage well before the well rounded variety existed. Kale was a significant crop in Roman times; it became a basic staple for peasants in the Middle Ages and it was brought in the United States by the English in the XVII century.
Kale is one of the most resistant from the cabbage family; it can support temperatures as low as -15 °C but it doesn’t sustain high temperatures. Since it resists to cold temperatures and grows easily, kale was for a long time a very appreciated winter vegetable especially in Scotland, Germany, Holland and Scandinavia. Today, it is eaten the world over.
Kale has large stringy leaves, very curly, with a well-marked flavor. Their color varies from pale green to dark green, sometimes to blue-tinted green. Those leaves are not well rounded, a characteristic expressed by the Latin word which describes this variety of cabbage « acephala » and which means « without head ». Those leaves surmount a fine whitish and very fibrous stem, it can measure from 30 to 40 cm. Kale is so decorative that ornamental varieties were developed.