Family, Saxifrage. Greenish, often tinged with yellow or purple. Petals, none. Calyx, with 4 or 5 lobes, green outside, yellowish within. Stamens, 8 or 10, on a large disk. Styles, 2. Flowers', small, single or in cymose, leafy clusters, on slender, reclining stems. Leaves mostly opposite, small, thickish, round, or heart - shaped, slightly lobed. April and May.

The name is misleading, for the predominant color of the flower is not yellow. Cold swamps or wet places.

Three-seeded Mercury Acalypha virginica. - Family, Spurge. Flowers, monoecious, the staminate and pistillate each with a calyx 3 to 5-parted. The staminate are small, almost minute, clustered in front of a small bract, in spikes. The pistillate, either singly or 2 or 3 together, grow in the axils of large, palmately-cleft, fruiting, leaf-like bracts. Stamens, 8 to 16, the anthers often being curved. Styles, 3, and the capsule is 3-seeded. Leaves, alternate, petioled, ovate or oblong, with stipules. July to September.

The plant is somewhat hairy, 18 to 20 inches high, turning reddish or purplish late in the season. It is a homely, nettle-like weed. In dry fields and open places, New England to Minnesota, southward to Florida.