Botanical Name: Eryngium aquaticum
Common Name: Marsh Rattlesnake Master, Corn Snakeroot, Bitter Snakeroot, Eryngo, Marsh Eryngo, Blue Snakeroot
Description: Very cool Florida native perennial for the sun to part sun areas of your garden. The blooms vary in color from a pale whitish-blue to a rich lavender or cornflower blue. Flowerheads are about 1/2” to 1” in diameter, globular, and are surrounded by spiny bracts. They are borne near the tops of multi-branched, erect stems. Leaves are sessile, linear, and alternately arranged. Leaf margins are entire or may be finely toothed.
Marsh Rattlesnake Master typically flowers summer through late fall. A variety of pollinators are attracted to its flowers including butterflies. It is especially valuable to native bees. Its natural habitat is in sunny marshes and swamps, along pond edges, and in ditches in moist to wet, acidic soils. Quickly grows 2-4′ tall x 1-2′ wide. Not considered extremely drought tolerant. This plant does well in a garden that is sunny and moist, but it cannot take consistent water submersion. A basal rosette of leaves stays green through the winter in Florida. It is a short-lived perennial. If grown in fertile soil or too much shade it will develop a more sprawling habit. Taller plants may need support from staking or by placing next to other plants they can lean on. The interesting foliage and flowers are great in cut and dried arrangements. No serious issues with insects, diseases, or other plant problems. This plant does not tolerate root disturbance, so leave it where you initially plant it.
Not salt tolerant of inundation by salty or brackish water. Low/no tolerance of salty wind or direct salt spray.
This plant in 1-gallon containers is 1-2′ tall.
Plant Lore: The common name rattlesnake master may have come from its use in Native American culture as a remedy for snakebites. Genus name comes from an ancient Greek name used by Theophrastus for a plant which grew in Greece (probably Eryngium campestre) or is a Greek reference to the prickly or spiny nature of plants in this genus. Specific epithet means growing near or in water.
Florida Hardiness Zones 8 – 9