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.
In deposits containing remains of recent plants as seeds no trace has as yet been found of this plant. It is widespread, occurring in the Arctic and Temperate Zone, in Arctic Europe, Asia, the Himalayas up to 17,000 ft., South Africa, Australia, and North America. It is found in every county in Great Britain, except S. Lincs, Stirling, North Perth, Westerness, Main Argyle, and is absent from counties west of the Caledonian Canal, except Caithness. It is found in Ireland.
The Winter Cress is fond of waysides, where it grows in clumps on the banks of the ditches. Probably its use as a salad may be to some extent responsible for this. Elsewhere it can be found along the banks of streams, ponds, rivers, and lakes, growing in more or less damp or moist conditions, but it is frequently to be found also on rubbish heaps and in waste places with other plants used in garnishing.
It has an erect habit, having a single, rarely branched, usually smooth, rarely downy, angular, main stem, with radical leaves, with a large terminal and smaller paired lobes, and with rounded lobes, and the upper leaves are inversely egg-shaped, sometimes arranged on either side of a common stalk and toothed. This gives it a strict or rigid habit. It grows in a clump, a number of plants in association in flower being a pretty picture, as the flowers are numerous. The under-side of the leaves is frequently purple, owing to the presence of anthocyan or red colouring matter, as in many moisture-loving plants.
It may be recognized by the above characters, and the small yellow flowers (1/3 in. in diameter), which grow in loose racemes, with pods, either closely united throughout or slightly spreading. The pods have an awl-shaped point and are square, and are broader than the flower-stalks. It grows to a height of 2 ft. The flowering stage lasts from May to August. The plant appears to be biennial, not perennial, as usually stated.
On each side of the two shorter stamens (there are six stamens altogether), at the base of the sepals, there is a small fleshy, green honey - gland, and between each longer pair a larger gland, external to their base, and also where the short stamens are abortive or functionless. In fine weather a drop of liquid (colourless) may be seen on each of the stamens. The anthers are situated irrespective of the position of the honey-glands. The longer stamens make a revolution of 90 degrees towards the short stamens, and exceed the stigma, from the time when the anthers open after the flower expands till the anther is completely covered on one side with pollen. The two short anthers on a level with the stigma are still turned towards it after opening, and the anthers are placed as in Water Cress, while the glands are as many as in N. sylvestre. Winter Cress is dispersed by its own agency. When the pods are dry they become tense and burst, and the light seeds are scattered to some distance.
Photo. Rev. C. A. Hall - Winter Cress (barbarea Vulgaris, Ait.)
This plant grows on sandy loam or clay.
Dodonaeus gave the name Barbarea, and it was formerly called Herb St. Barbara, hence the first Latin name, the second alluding to its common occurrence. The English names are St. Barbara's Herb, Cassabully, French or Winter Cress, Winter Rocket, Wound Rocket, Yellow Rocket. It was called Wound Rocket, as Turner says, because it was held to stanch wounds. St. Barbara's Day falls on 4th December. Winter Cress was used in winter as a salad, according to Lyte, whence the names, and others in French, Dutch, and Latin. It was formerly said to have formed the Crown of Thorns, but this seems unlikely.
In Sweden it is eaten and boiled. It is or was formerly used as a salad, though inferior to ordinary Water Cress, and without any distinctive flavour.
Essential Specific Characters: 26. Barbarea vulgaris, Ait. - Stem (flowering) angular, erect, radical leaves dark-green, shining, lyrate, terminal leaflet orbicular, upper leaves obovate, dentate, flowers yellow, numerous, style distinct, pods appressed, with subulate point, short.