Mile-A-Minute Weed
Family: Smartweed, Polygonaceae.
Habitat: Nurseries, roadsides, wet meadows, wood borders, other sunny, moist areas. Not yet common in Ohio, but has spread rapidly through the northeastern states.
Life cycle: Annual.
Growth Habit: Persistent vine that can extend 20 feet.
Leaves: Unique, triangle-shaped leaves with saucer-shaped sheathes near the base of stems. 1-3 inch leaves are light green, turning reddish-brown in winter, and have sharp, curved prickles on the petioles and leaf veins.
Stem: Numerous sharp, backward-curving prickles.
Flower: White, inconspicuous, borne on short spikes.
Fruit: Pea-size, berrylike, fleshy, iridescent blue fruits.
The problem is…. This troublesome annual can grow six inches per day, suffocating other vegetation in its path. Seeds spread easily through waterways or by birds and animals. The weed was introduced accidentally with nursery stock from Asia. Mile-a-minute is not yet common in Ohio, but can be found through northeastern states.
Birds and animals that eat these blue berries have spread mile-a-minute weed into new areas.
The unusual triangular leaves of mile-a-minute weed, combined with jagged prickles, make identification easy. Note the saucer-like sheathes near the base of petioles.
Currently there are 21 weeds on the Ohio Prohibited Noxious Weed List:
- Shattercane (Sorghum bicolor) – February 8
- Russian thistle (Salsola Kali var. tenuifolia) – February 22
- Johnsongrass (Sorghum halepense L. (Pers.))
- Wild parsnip (Pastinaca sativa)
- Wild carrot (Queen Anne’s lace) (Daucus carota L.)
- Oxeye daisy (Chrysanthermum leucanthemum var. pinnatifidum)
- Wild mustard (Brassica kaber var. pinnatifida)
- Grapevines: when growing in groups of one hundred or more and not pruned, sprayed,cultivated, or otherwise maintained for two consecutive years. – February 15
- Canada thistle (Cirsium arvense L. (Scop.))
- Poison hemlock (Conium maculatum)
- Cressleaf groundsel (Senecio glabellus)
- Musk thistle (Carduus nutans)
- Purple loosestrife (Lythrum salicaria)
- Mile-A-Minute Weed (Polygonum perfoliatum) – March 7
- Giant Hogweed (Heracleum mantegazzianum)
- Apple of Peru (Nicandra physalodes) – February 28
- Marestail (Conyza canadensis)
- Kochia (Bassia scoparia)
- Palmer amaranth (Amaranthus palmeri)
- Kudzu (Pueraria montana var. lobata)
- Japanese knotweed (Polygonum cuspidatum)
Each week, for the next 21 weeks, I will post information and pictures on how to identify these invasive and harmful plants.