Viola glaberrima (Gingins ex Chapman) House. Section: Chamaemelanium. Phen: Chasmogamous flower Mar-May; chasmogamous fruit Apr-Jun; cleistogamous fruit Jul-Aug. Hab: Rich mesic to wet-mesic forests on lower slopes and bottomlands, especially over mafic or calcareous rocks. Dist: Sw. PA, s. OH south to se. KY, sw. NC, c. NC, and nc. SC.
ID notes: In chasmogamous flower, this species might be confused with other caulescent yellow-flowered species with leaf blades longer than broad, such as occasional specimens of V. eriocarpa and V. hastata. It differs from V. eriocarpa in its solitary stems with 1 or no basal leaves, cauline leaves clustered in the uppermost fourth of the plant, and cauline leaf blades with rounded to cuneate base; and from V. hastata in leaf blades rhombic-ovate or ovate with a cuneate to rounded base and uniformly green upper leaf surface. In fruit, besides the above distinctions, it can be separated from V. canadensis (and V. rugulosa, not in our region) by the fewer crenate-serrate teeth on the leaf blade margins, and the small herbaceous stipules. Its solitary stem with leaves clustered at the top, and entire stipules distinguish it from the caulescent rostrate violets often growing with it (V. labradorica, V. rostrata, and V. striata).
Origin/Endemic status: Endemic
Taxonomy Comments: Usually synonymized under V. tripartita without taxonomic recognition or treated as a variety of that species, but recent studies confirm that this and the earlier synonym V. tenuipes are distinct from V. tripartita and from each other, each warranting species rank.
Synonymy: = Ballard, Kartesz, & Nishino (2023); = Viola tripartita Elliott var. glaberrima (Ging. ex Chapm.) R.M.Harper – G, Pa, RAB, S, W, Ballard () (in prep); < Viola tripartita Elliott – C, F, Fl2, FNA6, K1, K4, Tn, Va, WH3, WV, McKinney & Russell (2002)