Aerial photo taken on July 17, 2019 shows tourists visiting a verbena field in Binhai New Area of north China's Tianjin. (Xinhua/Yue Yuewei)
Butterflies rest on verbena flowers in Binhai New Area of north China's Tianjin, July 17, 2019. (Xinhua/Yue Yuewei)
Butterflies fly over a verbena field in Binhai New Area of north China's Tianjin, July 17, 2019. (Xinhua/Yue Yuewei)