TY - JOUR T1 - An expanded circumscription of Medicago (Leguminosae, Trifolieae) based on explosive flower tripping JF - Willdenowia Y1 - 1987 A1 - E. Small A1 - P. Lassen A1 - B.S. Brookes SP - 415 EP - 437 VL - 16 ER -