So we do actually have a native purple loosestrife. It is much smaller and daintier than its overbearing cousin. Typically growing 2-3 feet tall with a rhizomatous habit that is not invasive though it can form decent patches. Tends to wind its way through taller vegetation and cannot really take over space. Full sun and a wet to moist soil is preferred. Sparse, purple flowers appear June-July. An attractive plant for a wet meadow or rain garden. Zone 3-8. Mid-west ecotype.