Chelone is a genus of four[1] species of perennial herbaceous plants native to eastern North America.[1] They all have similarly shaped flowers (which led to the name turtlehead due to their resemblance to the head of a turtle), which vary in color from white to red, purple or pink.[1] Chelone cuthbertii, C. glabra, and C. lyonii are diploid and C. obliqua is either tetraploid or hexaploid, depending on their slight differences in morphology and localities.[1]
Chelone is derived from Greek meaning ‘turtle-like’, in reference to its turtle head-shaped corollas.[2]
The closest relative of Chelone is Nothochelone from western North America.[1] [3] [6] Nothochelone nemerosa is the species most closely related to the genus [3] [6]. Chelone is more closely related to it than to other members of the family such as snapdragons, plantains, and foxglove.[3]
Chelone glabra is the most widely distributed species of the genus: from Georgia to Newfoundland and from Mississippi to Manitoba; [5] [6] the other three are found in more restricted areas.
Chelone cuthbertii is found in two areas: the Blue Ridge of North Carolina and the coastal plain of Virginia.[1] [5] [6]
Chelone lyonii is found in the Blue Ridge of Tennessee, North Carolina, and South Carolina.[1] [5] [6]
Chelone obliqua is found as tetraploids in the Blue Ridge, or hexaploids in two areas: Tennessee to Arkansas and Michigan, or the Atlantic coastal plain from South Carolina to Maryland.[1] [5] [6]
The relationship between the different populations is complicated and it appears that C. obliqua in fact has arisen several times from diploid ancestors of the other three species.[1] [5] [6] The four species seem to have diverged recently.[1] [5] [6]