Mercurialis
(so named after Mercury, who is supposed to have discovered some virtues in the genus). Mercury. ORD. Euphorbiaceae. A genus comprising half-a-dozen erect herbaceous plants, with small, green, dioecious flowers, and opposite leaves. They are uninteresting weeds, widely distributed over the temperate regions of the globe. M. perennis, the Dog's Mercury, a native of Europe and North Africa, is a poisonous plant, which turns dull bluish-green when dried; and a deep blue dye, of a fugitive nature, may be obtained from it.