Watercress- in a Tennessee brook.

I used to see, in springs past, people wandering through a marshy brook in Percy Warner Park along Highway 100 across from Vaughn's Gap Road. The foragers were Asians. I never knew what they were picking. Until today. Today I found watercress growing and blooming along a running brook at Steveaway Farm in Pasquo. I had never seen it before. It was on private property, and I did not dare collect it, so I guess I will have to wait to taste Watercress sandwiches. I might be able to find some at Whole Foods. It is probably $20.00 a bunch