With short fat seed cases, I am inclined to think this is Rorippa nasturtuium aquaticum, whose seed cases are straight to curved and 1-2 cm long, 2-2.5 mm wide, rather than Rorippa microphylla, whose seed cases are curved and 1.5-3 cm long, 1-2 mm wide.
The name Nasturtium microphyllum is already in the CNM database as a synonym of Rorippa microphylla. Vicflora does not follow APNI for these two species.