On a recent tour of the Impressionism plants displays, our docent pointed out various sortd ofg something called "Angels Tongue." as a many year
I have checked the common name list for the present display of flowers in the Impressionism garden exhibit, but no plant has the common name of Angel's tongue. There is a plant named Penstemon that has a common name of Beard Tongue, ref. The NYBG Garden illustrated Encylopedia of Horticulture, Thomas H. Everett. Penstemon is almost exclusively of North American provenance (one of the about 250 species is native to Central America and one occurs in northeastn Asia). Penstemon belongs in the figwort family. Its name, sometimes incorrectly spelled Pentstemon, derives from the Greek pente, five, and stemon, a stamen. It alludes to the flowers having five stamens, counting the one stamiode as such.
Hope this helps.
Courtesy of the NYBG Plant Information Service