Sinapis Alba, Sinapis Nigra.
White mustard (Sinapis alba) seems to be indigenous to the southern countries of Europe and Western Asia, from which, according to Chinese authors, it was introduced into China. Formerly it was not distinguished from black mustard. Its cultivation in England is quite recent, but it is now an abundant weed in many sections. White mustard, in common with black mustard, is an exceedingly popular, stimulating condiment, and is preferred, on account of its color as well as its mildness, to the black mustard. The "mustard seed" of the Bible is the product of a tree (Salvadora persica), and is not the same as the plant now known under that name. (J. H. Balfour, Plants of the Bible.)
Black mustard (Sinapis nigra) is an herb found over the whole of Europe, excepting the extreme north. It also abounds in Northern Africa, Asia Minor, the Caucasian region, Western India, Southern Siberia, and China, as well as in North and South America, where it is now naturalized. It was known to the ancients, Theophrastus (633), Dioscorides (194), Pliny (514), and others noticing the plant. In early times it seems to have been used more as a medicine than as a condiment; but 300 B. C., Diocletian speaks of it as a substance used as a condiment in the eastern part of the Roman Empire. During the Middle Ages, Europeans esteemed it as an accompaniment to salted meats. The Welsh "Meddygon Myddfai" (507), of the thirteenth century, commends the "Virtues of Mustard." Household recipes of the thirteenth and fourteenth centuries constantly mention mustard under the name senapium. The convent lands of France produced it as a part of their revenues, A. D. 800. Black mustard is naturally of great importance, the credit of its introduction being, as with other substances of a similar nature, due to the observing "empiricists." The Bible reference (see Sinapis alba) applies alike to Sinapis nigra.