A perennial herb found in generally moist soils There are 2 recognized varieties – var. lanceolata leaves are lance-oblong, hairless or sparsely covered in soft hairs; var. vulgaris leaves are egg-shaped to oblong and slightly larger than var. lanceolata, the upper surface hairless or variously covered in stiff hairs. This species (or at least one of the varieties) is generally considered native to North America.