That's right! This is one of the real Nasturtiums. Those identity thieves in the garden are unrelated. On the other hand, those ID thieves are safe to eat. Watercress is tastier, but easily picks up biological and chemical toxins from the water it grows in. That's why we rarely see it offered as a salad green these days. This Eurasian native is very similar to another watercress, N. officinale, and is often called onerow yellowcress to differentiate the two. It's now seen around the world, and with us it has been reported from AK, AL, AR, CT, GA, HI, ID, IN, KY, MA, ME, MI, MN, MS, NC, NE, NH, NM, NY, OR, PA, RI, TN, VA, VT, WI, WY, BC, MB, NB, NF, ON, PE, QC, and SPM. Ives Fen Preserve, Lenawee Co MI, 6/18/11.