There are two hundred and twenty five non-native plants on Midway Atoll with Golden Crownbeard being the most invasive. In 2000 Golden Crownbeard covered 38% of the Eastern Island and 13% of Sand Island. Golden Crownbeard was probably brought to the atoll through seeds in soil imported to Midway.

Golden Crownbeard is an annual flowering shrub in the family Asteraceae. It is native to both North America and the tropics. Golden Crownbeard normally grows from one to five feet tall, but on Midway it grows up to eight feet tall. The vegetation is a grayish-green and the plant may have dozens of half inch wide yellow flowers. The leaves are ovate and half an inch wide, two and a half inches long.

Golden Crownbeard blocks the sun from native plants, competes with them for nutrients and water, though the plant is drought tolerant. Golden Crownbeard also produces chemicals that are harmful to native plants. Each flower produces up to three hundred and fifty seeds. The plant self seeds annually and the seeds are dispersed by the wind.

Midway is home to several species of endangered groundnesting seabirds and Golden Crownbeard decreases their nesting habitat because the birds won’t nest in the Golden Crownbeard stands. Stands of the plant can also grow up quickly around nesting sites preventing adult birds from feeding their chicks and preventing the chicks from getting to the ocean when they are fledging. This causes chicks to starve to death. Golden Crownbeard also hosts aphids and scale insects that attract and feed ants. The ants then may attack chicks or feed on eggs.

A management plan for Golden Crownbeard began on Midway in the 1990s but is very time and labor intensive as most methods of removing the plant would further endanger the seabirds. The program has consisted mostly of hand-pulling the plants, mowing and applying herbicide when possible. Areas where Golden Crownbeard has been removed are planted with native plants.

For more information on Midway Atoll or to help the effort to protect Midway and the seabirds please go to http://www.friendsofmidway.org/

Image from Forest & Kim Starr: http://www.hear.org/starr/

(Information from: http://www.abcbirds.org/conservationissues/threats/invasives/verbesina.html and http://www.friendsofmidway.org/Verbesina_on_Midway_Atoll_Brochure.pdf and personal communication with Christy Finlayson: http://www.umainetoday.umaine.edu/issues/v7i5/student.html)