Black mustard

Brassica nigra

Black mustard - an annual herb, growing up to 6 feet tall. The leaves of black mustard are pinnately divided at the base and toothed. The upper leaves are smaller and narrower than the lower ones. Yellow flowers (May-July) produce pods (June-October) containing the tiny brown to black seeds.

In spring endless acres of yellow-blossomed black mustard plants brighten waste areas across the land. In time the graceful flowers produce brown to black seeds that are among the most powerful caustic agents known. The seeds of black mustard contain two chemical compounds, myrosin and sinigrin. When mixed with water, the chemicals produce a volatile oil, a tiny drop of which may cause skin blisters or a burn.

This oil is the basis of the renowned mustard plaster that doctors in past generations prescribed, and mothers had the task of applying, for bad chest colds and bronchial conditions. The plaster consisted of a mixture of powdered mustard, flour, and water spread between two soft pieces of cloth such as flannel, which were placed on the chest. If the plaster was left on too long or if the preparation was too strong, the skin blistered.

The plaster was effective because the mustard seed oil is a counterirritant - an agent that, when applied externally to an inflamed area, causes the blood vessels to dilate. The resulting increased blood supply to the area carries away the toxic products that produced the original inflammation.

Parts used

The seeds.

Uses

Ancient Greek physicians prescribed black mustard plasters for lung congestion; Anglo-Saxons used them for bronchial problems. Research shows that black mustard seeds are an effective external agent for curing below-surface inflammations. The seeds of black mustard are also the flavoring in table mustard. The greens are a nutritious food, either cooked or added to salads.

The rubefacient action causes a mild irritation to the skin, stimulating the circulation to that area and relieving muscular and skeletal pain. Its stimulating, diaphoretic action can be utilised in the way that cayenne and ginger are. For feverishness, colds and influenza, black mustard may be taken as a tea or ground and sprinkled into a bath. The stimulation of circulation will aid chilblains as well as the conditions already mentioned. An infusion or poultice of black mustard will aid in cases of bronchitis.

Habitat & cultivation

A native of Europe, black mustard now grows wild throughout most of North America.

Constituents

Black mustard contains mucilage, fixed oil, volatile oil, sinigrin. Actions: rubefacient, irritant, stimulant, diuretic, emetic.

How much to take

Poultice: Black mustard is most commonly used as a poultice which can be made by mixing 100 grams (4 ounces) of freshly ground mustard seeds with warm water (at about 45°C) to form a thick paste. This is spread on a piece of cloth the size of the body area that is to be covered. To stop the paste sticking to the skin, lay a dampened gauze on the skin. Apply the cloth and remove after 1 minute. The skin may be reddened by this treatment which can be eased by applying olive oil afterwards.
Infusion: pour a cup of boiling water onto 1 teaspoonful of black mustard flour and leave to infuse for 5 minutes. This may be drunk three times a day.
Foot bath: make an infusion using 1 tablespoon of bruised seeds to 1 liter (2 pints) of boiling water.

Collection & harvesting

The ripe seed of black mustard pods are collected in the late summer. Tap the seeds out and dry in a thin layer.

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