It took me a great deal of searching to identify this plant. I finally discovered it is Impatiens gladulifera, but I found over a dozen common names including Indian touch-me-not, ornamental jewelweed and policeman’s helmet.
These wildflowers were nestled among the tall grass between a dike path and a slew in southwest Washington State. The plant can grow up to six and a half feet tall. Its red tinted stalk and stems give it a distinctive look. Oval leaves come to a point and have parallel veins and fine sawtooth edges.
Although I didn’t test this myself, the seeds can be distributed over 20 feet when the seed pods are disturbed.
Impatiens gladulifera is native to the Himalayas. It can become an invasive species is some areas, although I discovered only a few plants myself.