(n) showy perennial of marshlands of eastern and central North America having waxy lanceolate leaves and flower with lower part creamy white and upper parts pale pink to deep purple, Syn. shell-flower, turtlehead, Chelone glabra, snakehead, snake-head
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
n. (Bot.) An American perennial herb (Chelone glabra) having white flowers shaped like the head of a turtle. Called also snakehead, shell flower, and balmony. [ 1913 Webster ]