Oriental False Hawksbeard (Youngia japonica, 黄鹌菜).
On sunny Monday, the fields by the river were full of flowers: wide swathes of white chickweeds, shepherd's-purse and clover, blue speedwells and cucumber-herb, thousands of scattered purple violets, and a variety of yellows: dandelions, false hawksbeard, buttercups and wordsorrels. Freezing temperatures have come and, except for the resilient white clovers, the wild flowers are all back into hiding.