Blueflower Eryngo, Marsh Eryngo or Rattlesnake Master are all some of the common names for, Eryngium aquaticum, a very interesting and useful plant in bog gardens or even backyard ponds. The common name 'Rattlesnake Master' is a reference to the medicinal qualities of this plant and the fact that it has been used to treat Rattlersnake bites. This plant has basal leaves that are paddle shaped, linear to oblong-lanceolate and it forms a nice, relatively small attractive mound of foliage. The great point about this plant is not only the showy lavender to purple sputnik (spiny ball shaped flower heads) in the late summer into fall, but the fact that it is not aggressive in most backyard bog gardens or even pond margins. This plant grows in coastal marshes and is adapted to salt air, partial to full sun in moist to wet soil. It attracts butterflies and bees. Host for Black Swallowtail Butterfly.