At over 4,000 meters above sea level, botanist Xue Jingqi and his colleagues felt their heads throbbing with altitude sickness.
Local Tibetans guided them as they searched carefully in rocks near Shangri-La, southwest China's Yunnan Province.
Then their malaise lifted as they found rare wild peonies they had been looking for.
The team from the Chinese Academy of Agricultural Sciences (CAAS) carefully collected the seeds and brought them back to Beijing as part of a conservation program for endangered plants.
But in the lowland climate, almost all the seedlings were dead the following year.
The scientists returned to the plateau to collect new seeds, which they took to the relatively cooler Yanqing District, in the north of Beijing. The seedlings blossomed after careful cultivation, but then a sudden late-spring chill killed most of them.
"It was very frustrating that years of work went for nothing, but we soon improved the program," Xue said.
The team developed an efficient breeding method that greatly shortened the peony breeding cycle.