The common name is apt, for the flower does indeed resemble the protruding head of a turtle.
1. Corolla white or greenish yellow, rarely slightly pink tinged apically; staminodium greenish; sepals obscurely if at all ciliate; leaf blades (3.7–) 4.5–15 times as long as broad.
1. Corolla pink-purple throughout; staminodium white; sepals finely and closely (though minutely) ciliate; leaf blades ca. 2–5 times as long as broad.
2. Main stem leaves gradually tapering to a petiole 0.5–1.5 cm long, the largest blades 3–4.5 cm wide.
2. Main stem leaves contracted to a petiole 1.5–3 cm long, the largest blades 4–8 cm wide.
All species found in Chelone
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. June 19, 2018. https://www.michiganflora.net/genus.aspx?id=Chelone.