July 15, 2020

A Brassicaceae Bully

Alliaria petiolata

Alliaria petiolata - Photo courtesy of Glen Mittelhauser/Maine Natural History Observatory

With its distinctive white cross-shaped flowers and toothed heart-shaped leaves, the biennial Alliaria petiolata is also recognizable by its smell: Any part of the crushed plant smells like garlic or onion. A member of the Brassicaceae family, garlic mustard seems innocuous enough but is considered an invasive in many states because of its ability to form dense stands, with mature plants reaching 3 feet in height. According to Invasive.org, “A high shade tolerance allows this plant to invade high-quality, mature woodlands, where it can form dense stands. These stands not only shade out native understory flora but also produce allelopathic compounds that inhibit seed germination of other species.” Garlic mustard is a European native, and it is believed it was brought in the mid-1800s to the East Coast for food and medicinal purposes. Its preferred locations include moist, shaded soil in forests and edges of woods and trails. In Maine, according to “The Plants of Acadia National Park,” Alliaria petiolata can be found on Mount Desert Island.

Wild Wednesday is a collaboration of Garden Maine and Glen Mittelhauser of the nonprofit Maine Natural History Observatory, www.mainenaturalhistory.org.