Turtle head - Chelone Glabra ~ ‘Black Ace’
Chelone glabra 'Black Ace' A tall, dark-leaved cultivar of our native white Turtlehead, 'Black Ace' grows best in medium to wet, rich humusy soil. Good for bog and rain gardens, around ponds, and for erosion control. ... It is rhizomatous (spreading by rhizomes), so it is best to let it naturalize in an informal garden.