Wild Watercress Question

Hi all,

I've got a watercress question. I was walking along a stream yesterday, and found what seemed like a huge patch of watercress. The plants were growing as a ground cover in slow moving shallow water. It was really like a tangled mass. Around the edges were a few watercress plants that had flowered (white flowers on top of a basal rosette). I tasted these, and they were very peppery. This is what I expect from watercress. However, when I harvested from the ground cover that had not flowered, most of it was just very bitter, and had very little peppery taste. It also seemed as if the ground cover was not growing in the classic basal rosette formation. Is it possible this isn't watercress? The leaf structure still matches the description of watercress (alternating leaves, lighter colored bottom, slightly lobed). Here's a picture:

yes, it is possible it's not watercress. This is always possible when wild harvesting/foraging. Taste testing is a good thing to do and to trust in the negative i.e. you taste it, it doesn't taste right, so you don't eat the plant until you confirm the ID.

Hard to tell when it's all in a clump like that, but the plant into the photo doesn't look like watercress to me.