Ask Mr. Smarty Plants

There is one member of the Lythrum genus, Lythrum alatum (winged lythrum), that is native to Indiana.  However, you may also be thinking of Lythrum salicaria, which is a non-native invasive plant. You have to realize there is probably a very good reason why this plant is forbidden to be sold in several states in North America. For some of those reasons, read this website from the Plant Conservation Alliance Alien Plant Work Group, Purple loosestrife or  Lythrum salicaria. Another article on this plant is from The Master Gardeners of Adams County, PA and Frederick, MD, Lythrum, a Noxious Weed, by Mary Ann Ryan, Adams Co. Master Gardener. At the Lady Bird Johnson Wildflower Center, we are committed to the use and propagation of plants native not only to North America but to the area in which the plant is being grown, so we would never recommend planting an invasive non-native, and no sources for it would appear on our Native Plant Suppliers lists. 

Both of these articles point out that even lythrum plants advertised as "sterile" are not. The plant spreads both by prolific seeding and root extensions from which fresh suckers grow. It can easily interbreed with and take over from the native lythrum, and soon crowd out native plants and clog waterways, disturbing or destroying native habitats.  Since you can never be sure what you are purchasing, we advise you not to try it at all. There are many other beautiful plants native to Indiana that belong there and will not try to take over. For instance, we went to our Recommended Species section, used Narrow Your Search to "herb" (herbaceous blooming plant) for Habit, "perennial" for Duration, and "wet or moist soil" for Soil Moisture, all characteristics of the Lythrum. You can use the same technique to search for others that you would like. 

Gentiana andrewsii (closed bottle gentian) - 1 to 2 ft. tall, blooms white, blue, purple August til frost

Lobelia cardinalis (cardinalflower) - 1 to 6 ft., blooms red May til October

Lobelia siphilitica (great blue lobelia) - 2 to 3 ft., blooms blue July to October

Thalictrum dasycarpum (purple meadow-rue) - 3 to 6 ft., blooms white, yellow, green, purple March to July

Gentiana andrewsii

Lobelia cardinalis

Lobelia siphilitica

Thalictrum dasycarpum