Euphorbia commutata Engelmann ex A. Gray. Phen: Mar-Jul. Hab: Rich forests and rock outcrops, over calcareous or mafic rocks. Dist: PA west to s. ON and MN, south to ne. and Panhandle FL and ne. TX.
Origin/Endemic status: Native
Taxonomy Comments: The southern var. erecta J.B.S. Norton may be worthy of recognition; we have both it and the typic var. commutata in our region. Var. erecta (ranging north to VA, KY, and MO) has all the cauline leaves oblanceolate and with petioles 5-12 mm long; var. commutata has leaves varying from oblanceolate to obovate or ovate, the upper leaves usually broad and sessile.
Synonymy: = Ar, F, Fl2, FNA12, Il, K1, K3, K4, Mi, Pa, RAB, Tn, Va, W, WH3, WV, Govaerts, Frodin, & Radcliffe-Smith (2000), Mayfield (2013); > Euphorbia commutata Engelm. ex A.Gray var. commutata – C, G; > Euphorbia commutata Engelm. ex A.Gray var. erecta Norton – C, G; > Galarhoeus austrinus – S; > Galarhoeus commutatus (Engelm.) Small – S