Brassica oleracea var acephala, is a different species from chinese kale, B. oleracea var alboglabra, but the two plants have several features in common. Both are rather coarse and strongly flavoured in comparison with the more delicate cabbages of their respective regions; both have tough stems and are good only when young.
Kale and cabbage are varieties of the same species, and both are descended from the same wild ancestor. Kale is the more primitive of the two, and was the ordinary greenstuff of country people in most parts of Europe until the end of the Middle Ages, when the ‘headed’ cabbages were bred. In England kale was known as cole or colewort. Kale (or kail) is the Scottish name, and its continued prevalence is significant. Kale can grow in hard climates where the more delicate cabbages cannot, and still remains in common use in northern regions. There was even a ‘Kailyard school’ of Scottish writers, of whom