Martine, Christopher, Department of Biology, Bucknell University, 1 Dent Drive, Lewisburg, PA 17837, ctm015@bucknell.edu; Henry, Kaitlin, G, Biology, Bucknell University, Jewitt, Amy L., iMapInvasives Program, Western Pennsylvania Conservancy, Pennsylvania Natural Heritage Program, Rachel Carson State Office Building, Harrisburg PA 17105; Ciafre, Claire, Western Pennsylvania Conservancy, Pennsylvania Natural Heritage Program, Rachel Carson State Office Building, Harrisburg, PA 17105; Williams, Beth H.; Newhart, PJ; and Sain, Melody P., Department of Biology, Bucknell University, 1 Dent Drive, Lewisburg, PA 17837.
Lysimachia vulgaris (garden loosestrife, Primulaceae) is a yellow-blooming perennial wildflower native to wetlands of Europe, western Asia, and northern Africa. The species has been listed as ecologically invasive in large portions of the United States and has in many places been banned from sale, but its status in the Mid-Atlantic region has thus far been poorly assessed.
Our recent surveys in the Susquehanna River valley have shown that garden loosestrife is more abundant in this system than previously known, with multiple new records established between the Lewisburg, PA area and the southern border of the state. Incursions in many sites are quite dense, with the plants often dominating the frequently-inundated hydrologic zone between water-willow (Justicia virginiana) and lizard-tail (Saururus cernuus) patches at the water’s edge and the upper and less-disturbed areas of woody plant recruitment. At times, garden loosestrife co-occurs with the unrelated purple loosestrife (Lythrum salicaria, Lythraceae), but also appears to exploit niches where purple loosestrife is not abundant. When combined with verified observations posted to iNaturalist, iMapInvasives, and EDDMapS the new records for garden loosestrife suggest that this species is a quickly-emerging invasive plant in riparian corridors throughout the state and an increasing threat to native plant diversity and natural community assemblage.
Invasive species, Lysimachia, loosestrife, Susquehanna
