Rough bugleweed Lycopus asper Description Native to areas west of the Great Lakes. First discovered in Michigan in 1892 in Port Huron. Habit Leaves Sessile, unlobed, and usually unstalked. Oblong to inversely lance-shaped, 1.5-4 cm long and 0.25-1.375 cm wide. Tapers to a point and decreases in size as they ascend the stem. Upper surface rough with minute, stiff hairs but can also be hairless. Serrate margins, coarsely and evenly toothed with sharp, forward-pointing teeth. Smell like mint when crushed. Stems Stout, erect, green in color, typically unbranched Source: MISIN. 2021. Midwest Invasive Species Information Network. Michigan State University - Applied Spatial Ecology and Technical Services Laboratory. Available online at https://www.misin.msu.edu/facts/detail.php?id=437. and hollow. Square-shaped with a single vertical groove. Flowers Inflorescence is a tight cluster of small, white, stalkless flowers. Pairs of clusters form false whorls on the upper 2/3 of the stem. 5 petals form a tube in the center and separate at the tip into 4 lobes. Fruits and Seeds Set of 4 egg-shaped, brown, hairless, ridged nutlets with one seed each. Depressed center with cork like ridges allowing them to float. Habitat Native to the United States / Mississippi River basin. Can be found in marshes, swamps, shorelines and other wet areas. Reproduction By seed and vegetatively by rhizomes. Similar American water horehound (Lycopus americanus), Clasping water horehound (Lycopus amplectens), Taperleaf water horehound (Lycopus rubellus), Northern bugleweed (Lycopus uniflorus), and Virginia water horehound (Lycopus virginicus) Monitoring and Rapid Response Source: MISIN. 2021. Midwest Invasive Species Information Network. Michigan State University - Applied Spatial Ecology and Technical Services Laboratory. Available online at https://www.misin.msu.edu/facts/detail.php?id=437. No known biological, physical or chemical control methods. Credits The information provided in this factsheet was gathered from the Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS). Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org). Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com). Source: MISIN. 2021. Midwest Invasive Species Information Network. Michigan State University - Applied Spatial Ecology and Technical Services Laboratory. Available online at https://www.misin.msu.edu/facts/detail.php?id=437..