Figure 31.Button-snakeroot (Eryngium aquaticum)
Eryngium yuccifolium Michx.
Eryngium, eryngo, water eryngo, corn snakeroot, rattlesnake master, rattlesnake-weed, rattlesnake flag.
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.
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.
The rootstock, collected in autumn.