Asclepias circinalis (Decne.) Woodson Asclepias circinalis (Decne.) Woodson in Ann. Missouri Bot. Gard. 28: 207. 1941 sec. Juárez-Jaimes & al. 2007≡Acerates circinalis Decne. in Ann. Sci. Nat., Bot., sér. 2, 9: 322–3, t. 11C. 1838 syn. sec. Villaseñor & al. 2010