TRIFOLIUM, TREFOIL; a genus of the decandria order, belonging to the diadelphia class of plants. There are 43 species; of which the most remarkable are, 1. The melilotis officinalis, or melilot, is a native of Britain, growing in corn-fields and by the waysides, but not common. The stalk is erect, firm, striated, branched, and two or three feet high: the leaves ternate, smooth, obtusely oval, and serrated: the flowers are small, yellow, pendulous, and grow in long close spikes at the tops of the branches: the pod is very short, turbid, transversely wrinkled, pendulous, and contains either one or two seeds. The plant has a very peculiar strong scent, and disagreeable bitter acrid taste, but such, however, as is not displeasing to cattle. The flowers are sweet-scented. It has generally been esteemed emollient and digestive, and been used in fomentations and cataplasms, particularly in the plaster employed in dressing blisters; but is now laid aside, as its quality is found to be rather acrid and irritating than emollient or resolvent. It communicates a most loathsome flavour to wheat and other grain, so as to render it unfit for making bread.
2. The repens, white creeping trefoil, or Dutch trefoil, is common in meadows and pastures. It is well known to be an excellent fodder for cattle; and the leaves are a good rustic hygrometer, as they are always relaxed and flaccid in dry weather, but erect in moist or rainy.
3. The pratense, purple trefoil or clover, frequent in meadows and pastures. It affords a very plentiful fodder to horses and other cattle; but when they feed too greedily on the fresh herb, it blows them up in such a manner with wind, that unless they are speedily relieved, by tapping them in the belly or some other similar operation, they soon perish. In Ireland the poor people, in a scarcity of corn, make a kind of bread of the dried flowers of this and the preceding plant reduced to powder. They call the plant cham-broch, and esteem the bread made of it to be very wholesome and nutritive.