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..
Aquatic herbs, with thick rootstocks buried in the mud, oblong-elliptic nerved leaves without a distinct midvein, and slender terete scapes terminated by a cylindric spadix. Spathe enclosing the spadix when very young, soon parting and remaining as a sheathing bract at its base, or falling away. Flowers perfect, bright yellow, covering the whole spadix. Sepals 4-6, scale-like, imbricated upon the ovary (lower flowers commonly with 6, upper with 4). Stamens as many as the sepals; filaments linear, wider than the anthers, abruptly narrowed above; anthers small, with two diverging sacs opening by oblique slits. Ovary partly imbedded in the axis of the spadix, depressed, obtusely angled, 1-celled; ovule solitary, half-anatropous; stigma sessile. Fruit a green utricle. Endosperm none; embryo long-stalked. [Ancient name of some water plant, said to be from the Syrian river Orontes.]
A monotypic genus of eastern North America.
Orontium aquaticum L. Sp. PI. 324. 1753.
Leaves ascending or floating, depending on the depth of water, deep dull green above, pale beneath, the blade 5-12' long, 2'-$' wide, entire, acute or cuspidate at the apex, narrowed at the base into a petiole 4'-20' long. Scape 6'-24' long, flattened near the spadix; spadix 1 -2' long, 3"-4" in diameter, frequently attenuate at the summit, much thickened in fruit; spathe bract-like, 2'-4' long, 2-keeled on the back; usually falling away early; utricle depressed, roughened on top with 9 or 10 tubercles.
In swamps and ponds, Massachusetts to central Pennsylvania, south to Florida and Louisiana, mostly near the coast. Ascends to 2000 ft. on the Pocono plateau of Pennsylvania. Water-dock. Tawkin. April-May.