This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
There is, as usual in the case of most succulent plants, no instance of the occurrence of this plant or its seeds in Glacial, earlier, or later deposits. It is found generally from the coasts of Finland and the Bay of Biscay to the Black Sea. Two hundred years ago it was cultivated, and introduced to the Continent from Great Britain. It occurs in N. and W. Ireland. In Great Britain it is absent from W. Cornwall, S. Somersets, S. Essex, W. Norfolk, Carmarthen, Cardigan, Denbigh, Flint, S. Lines, Durham, Northumberland, Cheviotland; and in Scotland it is found only in Kirkcudbright, Wigtown, Ayr, Berwick, Linlithgow, Fife, Clyde Islands, Cantire, Islay, Hebrides, but occurs on the remaining coasts. It is on the decrease in some parts. It is found in the Channel Islands.
The wild form of Sea Kale, much used as a salad, is found on sandy and shingly sea-coasts, and it is a halophyte or salt-lover. It is also a xerophyte, though requiring moist conditions, and may be called a strand plant. With it grow Sea Rocket, Sea Purslane, Sea Milkwort, Sea Holly, and other maritime species.
The first Latin name is the Greek for cabbage, with the habit of which it agrees. It has a thick fleshy root, a stout stem much branched, with wide, wavy, rounded leaves, toothed, and bluish-green. The stem and leaves are smooth, and the plant is compact, and as broad as long. It grows in clumps.
The flowers are white, large, and distinct, in corymbs containing several racemes, and much branched. The outer anther-stalks are forked and long. The pods are blunt or egg-shaped, on ascending flower-stalks, with two joints, one forming a flower-stalk, and there is no style.
Sea Kale grows to a height of 2 ft. The Mowers are in bloom in June, July, and August. The plant is perennial, increased by division.
The diameter of the flowers is as much as 12 mm., and together they form a conspicuous head. The petals form a tube by being enclosed by the sepals. The stalks of the petals, the stamens, and pistil are yellowish-green before they turn violet.
The anthers are yellow. Below the longer stamens are two round honey glands, which are large and green in colour. Two smaller ones lie at the base of the shorter stamens. The anthers in the longer stamens lie between knoblike extremities, perhaps helping to guide the insect's proboscis. The stigma is ripe first when the flower expands, and is overtopped by the longer stamens. The honey is attractive to the larvae of a beetle (Meli-gethes), and they may help to cross-pollinate the flower. The flowers are large and conspicuous, white, with the longer anther-stalks notched. The habitat being maritime the plant is not open to insect visits in great numbers, and self-pollination becomes a necessity.
The fruit of Sea Kale is dispersed by its own agency. The pods do not open to let the single seeds fall out, but drop off, and the seeds germinate around the parent plant. The pods are apparently stalked, the lower joint being without seeds and serving as a stalk to the upper, 1-celled and 1-seeded.
The name Crambe, Greek for Kale, was given by Hippocrates, and maritima (Latin) refers to its habitat.
Sea Kale is called Sea Cabbage, Sea Cale, Sea Cole, Sea Cole-wort, Sea Kale.
It is cut by the people on the coast in the west of England, and used like asparagus, the young shoots being boiled. People watch for the shoots and leaves pushing up from below ground. It was first employed in the garden about 200 years ago, and the practice was also afterwards copied on the Continent. In the garden it is sown in rich sandy soil, blanched and covered up to promote a quick and white growth (to improve the flavour) under pots, kale pots being now the vogue. The roots are taken up, and forced in a hot-bed or forcing-house, or covered with straw, etc, in the open like rhubarb, a frame being placed over the stools before the litter is put on. It is easily forced, and is productive the first season after sowing seed.
Dr. Somerville Hastings
Sea Kale (Crambe Maritima, L.)
Essential Specific Characters: 38. Crambe maritima, L. - Stem erect, tall, leaves sinuate, broad, glaucous, pinnatifid, dentate, flowers corymbose, white, pods ovoid, large, on slender suberect pedicels.