This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Marsh herbs, with slender rootstocks, jointed stems and cordate leaves, their petioles sheathing the stem at the nodes, and small white flowers, in 1 or 2 dense elongated spikes opposite the leaves. Bractlets adnate to the flowers or to their minute pedicels. Stamens 6-8. Filaments filiform, distinct. Carpels united at the base. Styles as many as the carpels, recurved, stigmatic along the inner side. Fruit rugose, depressed-globose, separating into 3 or 4 one-seeded carpels. [Name Greek, lizard's tail, alluding to the long slender spike.]
Two species, the following typical one of eastern North America, the other of eastern Asia.
Saururus cernuus L. Sp. PI. 341. 1753.
Somewhat pubescent when young, becoming glabrous; stem rather slender, erect, sparingly branched, 2°-5° high. Leaves ovate, thin, pal-mately 5-9-ribbed and with a pair of strong ribs above, which run nearly to the apex, dark green, entire, deeply cordate at the base, acuminate, 3-6' long, 2-3 1/2' wide; petioles stout, shorter than the blades, striate; spikes few, very dense, longer than their peduncles, 4'-6' long, the apex drooping in flower; flowers fragrant; stamens white, spreading, about 2" long; fruit slightly fleshy, 1 1/2' in diameter, strongly wrinkled when dry.