Impatiens pallida is native to North America, and doesn't occur naturally in your area, Masud. Therefore, it had to have been a garden escape (this just means a plant that was brought over to grow in gardens - attractive or edible ones, usually - and has invaded into the wild) or a plant that was otherwise introduced intentionally or unintentionally. I imagine a great number of our North American weeds were introduced in seed grain shipments brought over from Europe mainly.
