June 28, 2017

O Pioneer

Centaurea maculosa - Spotted knapweed | Photo courtesy of Glen Mittelhauser/Maine Natural History Observatory

Centaurea maculosa – Spotted knapweed | Photo courtesy of Glen Mittelhauser/Maine Natural History Observatory

Centaurea maculosa may look familiar, given that its relatives include the iconic C. cyanus (bachelor button) and C. montana (mountain bluet). But this species is not native to North America and is considered a highly invasive plant across much of the United States and Canada. Known as spotted knapweed, it is thought the plant arrived in North America via an alfalfa shipment, first noted on the continent in the late 1800s. In 2000, all but five states in the U.S. reported its presence. So what makes this plant such an enemy? It is called a pioneer plant, the first to colonize a disturbed area. It is particularly adept at invading rangelands in the Northwest. Part of its “charm” is that it out-competes native species with its ability to draw water through its taproot more quickly, its high seed production and its lack of appeal as a food source. That last one translates into overgrazing of native species, which gives the non-native knapweed more opportunity to spread. Here in New England, the plant is present in every state and considered invasive in half of them. It can be found in every county in Maine.

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

In 2012, Glen began working to catalog the plants of Baxter State Park, which you can read about here and find out how to sponsor a plant of your own. Courtesy of a poll taken in 2012, Garden Maine is sponsoring this lovely plant.