References
Webb, D.H. 1980. A biosystematic study of Hypericum section Spachium in eastern North America. Ph.D. Diss., University of Tennessee, Knoxville. Google Scholar
Webb, D.H. 1980. A biosystematic study of Hypericum section Spachium in eastern North America. Ph.D. Diss., University of Tennessee, Knoxville. Google Scholar