Euphorbia alta Norton Euphorbia alta Norton, Annual Rep. Missouri Bot. Gard. 11. 1900 sec. Martínez-Gordillo & al. 2002=Tithymalus altus (Norton) Wooton & Standl., Contr. U.S. Natl. Herb. 16(4). 1913 syn. sec. Martínez-Gordillo & al. 2006