This section is from the book "Harper's Guide To Wild Flowers", by Caroline A. Creevey. Also available from Amazon: Harper's Guide To Wild Flowers.
Color, deep yellow. Sepals, 5, very small. Petals, small, 5 to 7. They fall easily. Stamens, indefinite. Pistils, numerous, in a small, round head. Leaves, 4 to 5 inches long, narrow or oblong, distantly toothed, on long, half-clasping petioles. Stems, ascending, sometimes rooting from the lower joints.
A smooth plant with flowers much like buttercups. Maine to Georgia and westward. In muddy places, swamps, etc.
 
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