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Have you seen this plant?

New invader on the scene and it isn’t pretty

Mile-a-minute vine found on Nantucket

Current distribution by county.
Check to see if any plants have these characteristics.
The vines can easily cover and smother. (photo courtesy of Les Mehrhoff)
 (photo courtesy of Les Mehrhoff)

As botanists, when we find a new or rare species it can be a joyous event. However, as an invasive plant ecologist, finding a species new to the island is not an occasion to be celebrated.

Recently, a couple summering on the island discovered a plant on their Pocomo property that looked dubiously familiar. In their home state, this is a known problem species. After bringing a sample to the UMASS Boston Nantucket Field Station and with a positive ID from Kelly Omand (Chair of the Invasive Plant Species Committee), the plant was confirmed to be Persicaria perfoliata, or mile-a-minute vine.

Mile-a-minute has never been recorded on Nantucket before. The nearest known populations to Nantucket are in Falmouth and it is sparse in the state. This plant is very concerning to the conservation community on Nantucket given its rapid spread in other areas of New England. The state of Connecticut, for example, launched a massive public campaign to document and eradicate the species in 2009. This campaign was successful in increasing the awareness of the species and, thus, the recorded number of occurrences. The eradication success has been spotty, however. The University of Connecticut maintains a mile-a-minute website which keeps up to date location information for the state. The animation of the spread by year is daunting.

What’s so bad about this plant anyway? As its name suggests, mile-a-minute is fast growing. A single adult plant of this Asian annual can, if left uncontrolled, produce over 2000 seeds and blanket an area over 20 ft. in diameter. Plants have been shown to grow as fast as 6 inches a day! This means it can quickly cover a large area and out-compete neighboring species. As a vine, it is a climber. While this is not a strangling vine, mile-a-minute covers and smothers shrubs and trees, thus shading the grasses and forbs below. Its fruits are bird-dispersed adding to the problem of seed spread. The specimen on Nantucket was found under a roost popular by birds.

What does it look like? Check out the pictures that accompany this article. Mile-a-minute vine is an herbaceous, annual vine that primarily invades disturbed areas. The delicate stems are reddish, highly branched and covered with small, curved spines. Circular, leafy structures (ocreae) surround the stem at the base of the petioles. The fruit are visible in late-July through the first frost, and are metallic blue to purple. The leaves are distinctly triangle shaped (like an equilateral triangle). Other plants may have similar vining habits and/or barbs but different leaf shapes. For more specific information on identification and guides to similar species, check out the following pages:

What can you do? Take a few moments to look at the images and ID included with this article. Should you see this plant, please note its location as exactly as you can (GPS, mark it on your phone map, or just note the nearest street address or other permanent marker). Take a few photos or a plant snippet if you can and report it to the Invasive Plants Species Committee of Nantucket. You can do so by contacting Sarah Bois ([email protected]) or Kelly Omand ([email protected]). Mile-a-minute vine is also surprisingly easy to pull up with the roots. If you do so, make sure to dispose of the plant with the household trash and not in the compost!

Early detection of this plant is the key to eliminating it and keeping it from spreading on the island. We have enough non-native invasive plant problems on the island, we don’t need one more!

Additional information:

Here is a great NPR story from 2009 on the Falmouth population.

MAM info page from the Invasive Plant Atlas of New England