INVASIVE SPECIES PROFILE: lyme grass ( Leymus arenarius ) Also known as sand rye grass, wild rye, blue lyme grass, and blue dune grass. Description This perennial grass can grow to 2-4 feet in height. Each evergreen leaf is bright, light blue to blue-green in color and about 12 inches long and 1/2 inch wide. Flowers are dense spikes that are blue-green in early summer and turn dark beige later in the year. Look-alikes The blue leaves often stand out clearly among the green leaves of the native American dune grass ( Ammophila breviligulata ). Lyme grass also has bigger seeds, tougher blades and stiffer seed stalk. Lyme grass could also be confused with wheatgrass (Elymus lanceolatus). While wheatgrass has a blue leaf blade, lyme grass has wider leaves, greater then 1/16 of an inch, while the wheatgrass leaves are smaller than 1/16 of an inch and curl inward to appear much smaller. Impacts & Habitat This plant is an ornamental grass native to Europe and Asia. It spreads primarily by underground stems (rhizomes), but also reproduces by seed. This grass can grow in most habitats, although it prefers well-drained sandy soil and full sun. It can handle extremes of heat and cold, and it is drought resistant. This plant is sold as an ornamental, and is used to control erosion. However, it can quickly become invasive on dunes. Of particular concern in the Great Lakes area is its ability to stabilize naturally shifting sand dunes of the Great Lakes. Control Mechanical removal is not effective because new plants sprout from rhizomes and root fragments left in the soil. Late summer herbicide treatment on the leaves and cutting and bagging seed heads can be very effective. Lyme grass seed heads Due to very successful treatments in 2010 and 2011 remaining plants are likely to be small and without seed heads. Lyme grass mixed with dead leaves from the previous growing season. Beach grass mixed with lyme grass Lyme grass mixed with beach grass The plant on the left is lyme grass. The plant on the right is beach grass. Lyme grass seed head stems (on left) stand tall and firm above the plant. The inflorescence is short with large, course glumes (flower parts). Beach grass seed heads (pictured in on the right and in the background of the picture on the left) are longer, lighter in color and typically start lower down within the beach grass leaves. Lyme grass leaves and seed heads mixed with beach grass leaves Beach grass center and left foreground and lyme grass in background and in foreground – right .