Eryngium aquaticum L.
Synonym.—Eryngium yuccifolium Michx.
Other common names: Eryngium, eryngo, water eryngo, corn snakeroot, rattlesnake master, rattlesnake-weed, rattlesnake flag.
Habitat and range: Although sometimes occurring on dry land, button-snakeroot usually inhabits swamps and low, wet ground from Connecticut and the pine barrens of New Jersey to Illinois and South Dakota and south to Texas and Florida.
Description: This plant has grasslike, rigid, parallel-veined leaves 1 to 2 feet in length and about one-half inch in width. The stout furrowed stem reaches a height of from 2 to 6 feet and is generally unbranched except near the top. . The insignificant whitish flowers are borne in dense, stout-stemmed heads from June to September. The stout rootstock is very knotty, with numerous short branches, and produces many thick, rather straight roots.
Part used: The rootstock, collected in autumn.
