This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
Quite a number of our common plants have been distinguished in popular nomenclature by the prefix "cow," and as a general rule it would appear to have been applied in depreciation, as in the parallel cases of "dog," "horse," and "hog," to signify coarseness or worthlessness. In the case of the Cow-wheat our forefathers had a notion that if its seeds were ground up with wheat the bread made from the flour would be black. One of the species (M. arvense) affects cornfields, and its seeds are like black grains of wheat, and from this fact the genus gets its scientific appellation from the Greek, melas, black, and puros, wheat. In addition the plants themselves turn black when dead and dry.
I. Common Yellow Cow-wheat (M. pratense) is an annual, partially parasitic upon roots, like Eyebright. The leaves are almost stalkless, very narrow, with even margins, and produced in pairs. The flower follows the general structure of the Scruphularineae (see pp. 33 and 50 ante). The calyx is five-toothed, the corolla. tubular, straight, dilated at the mouth and two-lipped, the upper with the edges turned back, the lower three-lobed. The four stamens will be found close under the upper lip, with the small stigma. It should be noticed that in this species, which is common in dry woods and on heaths, the pale yellow flowers assume a horizontal position, whilst the capsule is more deflexed. May to September.
II. Small-flowered Yellow Cow-wheat (M. sylvaticum) is a rare species, found in alpine woods from Yorkshire northwards. It has a small deep yellow corolla, which is borne more erectly than in pratense. Other points of difference will be found in the curved corolla-tube, and in the position of the capsule, which is not deflexed. Flowers July and August.
III. Purple Field Cow-wheat (M. arvense). This is a local species whose distribution in this country is restricted to Norfolk, Suffolk, Essex, Herts, and the Isle of Wight. Where it occurs it is a conspicuous item in the cornfield flora, by reason of its large spikes of flowers with their many colours. The bracts are reddish-purple, the corolla rosy, with yellow throat, and the lips a full pink. Flowers July and August.
IV. Crested Cow-wheat (M. cristatum). This also is a rare plant, confined to the Eastern counties of England, and affecting woods, copses, and cornfields. It has broad, heart-shaped, purple bracts, with long fine teeth. The flowers in a dense spike (not so large as in arvense); corolla-tube curved, yellow, the upper lip purple within. Flowers September and October.
- Scrophularineae. -