Evidence for natural hybridization between Primula beesiana and P. bulleyana, two heterostylous primroses in NW Yunnan, China
Yong-Peng MA, Xiao-Ling TIAN, Jing-Li ZHANG, Zhi-Kun WU, Wei-Bang SUN
J Syst Evol . 2014, (4): 500 -507 .  DOI: 10.1111/jse.12077