Newly blossoming at Centennial this week. As far as I can tell, this is Garlic Mustard, which sounds good, but evidently it’s a terrible weed that crowds out native plants. (Introduced from Europe.)

“Garlic mustard poses a severe threat to native plants and animals in forest communities in much of the eastern and midwestern U.S. Many native wildlflowers that complete their life cycles in the springtime (e.g., spring beauty, wild ginger, bloodroot, Dutchman’s breeches, hepatica, toothworts, and trilliums) occur in the same habitat as garlic mustard. Once introduced to an area, garlic mustard outcompetes native plants by aggressively monopolizing light, moisture, nutrients, soil and space. Wildlife species that depend on these early plants for their foliage, pollen, nectar, fruits, seeds and roots, are deprived of these essential food sources when garlic mustard replaces them. ” -Plant Conservation Alliance

Garlic Mustard (Alliaria petiolata)