Euphorbia violacea Greenm. Euphorbia violacea Greenm., Proc. Amer. Acad. Arts 33. 1898 sec. Martínez-Gordillo & al. 2002=Eumecanthus violaceus (Greenm.) Millsp. in Publ. Field Mus. Nat. Hist. Bot. Ser. 2(11): 415. 1916 syn. sec. Martínez-Gordillo & al. 2006