1) Bog plant 2) Chelone glabra 3) Marsh plant 4) Shell-flower 5) Snake-head 6) Snakehead 7) Swamp plant 1) Shellflower 2) Snakehead 
• (n.) An American perennial herb (Chelone glabra) having white flowers shaped like the head of a turtle. Called also snakehead, shell flower, and balmony.
snakehead noun 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
any of several North American plants belonging to the genus Chelone, of the figwort family, having opposite, serrated leaves and spikes of purple or white, two-lipped flowers.