P. aemula is efarinose, and is distinguished by its robust nature, several whorls of pale yellow flowers in which the oblong corolla lobes are patent (sometimes slightly bent back), leaf blade base is long attenuate and the blade is longer than the petiole. It was first collected on the Chungtien (Zhongdian) plateau, Yunnan but has also been found to the East of there in SW Sichuan.