Senna pentagonia (Mill.) H.S. Irwin & Barneby Senna pentagonia (Mill.) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 35: 255. 1982 sec. Irwin & Barneby 1982≡Cassia pentagonia Mill., Gard. Dict., ed. 8: Cassia no. 18. 1768 syn. sec. Irwin & Barneby 1982