Asclepias pringlei (Greenm.) Woodson Asclepias pringlei (Greenm.) Woodson in Ann. Missouri Bot. Gard. 28: 206. 1941 sec. Juárez-Jaimes & al. 2007≡Acerates pringlei Greenm. in Proc. Amer. Acad. Arts 34: 570. 1899 syn. sec. Woodson Jr. 1954