Urweltmammutbaum
Wan Chun Cheng or Zheng Wanjun (, 1908–1987) was a Chinese botanist. Initially one of the Chinese plant collectors who followed in the wake of the Europeans after 1920, he became one of the world's leading authorities on the taxonomy of gymnosperms. Working at the National Central University in Nanjing, he was instrumental in the identification in 1944 of the dawn redwood, "Metasequoia glyptostroboides" previously known only from fossils. The plant "Juniperus chengii" is named in his honour.