Collaborative North America/Eurasian Research on Lythrum salicaria and Other Invasive Species

The research examines the growth and genetics of Lythrum salicaria in native versus invasive habitats. Researchers include scientists from the US, Canada, Turkey and the Czech Republic. Volunteers are enlisted via the Internet to help make worldwide measurements of the species. The major question is to determine whether the differences in growth patterns in North America versus Eurasia are related to genetic differences in the species.

The ultimate goal is to determine is there are any environmental controls of Lythrum salicaria present in Eurasia, that may be of value in controlling this invasive species in North America.

Thus far, we have discovered that Lythrum salicaria height is tallest in the middle of the range in North America (e.g., Wisconsin) and shorter to the north and south (northern Quebec and northern Alabama, respectively). Common garden studies indicate that the species will grow outside of its current range in North America (e.g., Louisiana).

The next step is to determine if differences in growth can be attributed to genetic differences in the species. Lythrum salicaria in North America may have introgressed genes from native species of Lythrum in North America, and so may represent a type that is not present in Eurasia. Not enough data is currently available to model the height of Lythrum salicaria in Eurasia, so more volunteers are being solicited there.

	Contact: Dr. Beth Middleton USGS, National Wetlands Research Center Lafayette, LA 70506 beth_middleton@usgs.gov Website: http://www.nwrc.usgs.gov/special/purplel/index.htm