This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds and by rootstocks.
Time of bloom: June to August.
Seed-time: July to September.
Range: Rhode Island and New York to Minnesota, southward to
Georgia and Texas. Habitat: Wet grasslands, marshes, and borders of streams.
A very pernicious plant, nearly related to the Veratrum. It is specially obnoxious as a weed of wet meadows, for its long, narrow leaves make it much less conspicuous among the grass and hay than its larger and more deadly relative. It is poisonous to all stock, but particularly so to horses.
The stem springs from a large, thick rootstock, and is rather slender, simple, two to four feet or more high, very leafy, and roughish-downy near the top, as is also the flower stalk. Leaves narrow lance-shape to linear, often more than a foot long, a halfinch to about an inch wide, the lower ones narrowing to a sheathing base, the upper ones much smaller and sessile. Flowers in a large, dense, terminal, alternately branching, pyramidal panicle, six to eighteen inches long, each pedicel subtended by a small, long-ovate bract; each blossom about a half-inch broad, greenish white or creamy yellow, darkening to brown as they wither. They have no corolla but have six separate clawed sepals, oblong or sometimes heart-shaped or even slightly auricled, and spread flat, the claws bearing the six stamens and usually having at the base of the blades two conspicuous dark glands; some flowers simply staminate, others pistillate, others perfect, may all be found on the same stalk, but usually the lower ones are sterile. Capsules about a half-inch long, three-celled, the persistent styles making them triple-pointed, and each cavity contains about ten very flat and broadly winged brown seeds, easily distributed either by wind or by water.
From small areas the perennial rootstocks may be grubbed out; or, when of but one season's growth and before they have penetrated the soil very far, they can be quickly pulled when the ground is soft. Badly infested meadows require to be drained and put under cultivation. In every case, seeding should be prevented by close cutting at the beginning of bloom.