What country do both Limnocharis and Paulownia share?
Limnocharis: Limnocharis is a genus of plants in the family Alismataceae, native to Mexico, Central America, the West Indies and South America) but naturalized in China, India, and Southeast Asia as well. Paulownia:  They are present in much of China, south to northern Laos and Vietnam and are long cultivated elsewhere in eastern Asia, notably in Japan and Korea.
China