Wintercress ???

Wintercress ???

Observation - Wintercress ???. Description: Dense growths of leaves emerging from the water at or near the edge of a shallow (about 0.3m)channel off a chalk stream/river at the base of the bank. Only 2 seen flowering were on far bank but looked like crucifer's.. bright yellow four petals in loose r

Dense growths of leaves emerging from the water at or near the edge of a shallow (about 0.3m)channel off a chalk stream/river at the base of the bank. Only 2 seen flowering were on far bank but looked like crucifer's.. bright yellow four petals in loose raceme, couldn't make out any seed pods below the few flowers and photo pretty useless!