Plants That Won't Stay Put
1800s. Originally, it was promoted as livestock forage and as a means of erosion control.
In Missouri, kudzu can be found along highways where it was planted before it was found to be so invasive. It spreads over the ground or climbs on brush or trees, forming a dense tangle of vines that shades out any vegetation beneath it.
Kudzu can spread from vines that run along the ground or from underground stems called rhizomes. Its seeds are known to disperse over long distances, further increasing its spread. Cold winters can limit the growth of kudzu, but it has been found in northern Missouri, as well as farther south.
Multiflora Rose Rosa multiflora
This shrub was brought to the U.S. from Japan to use as a root stock on which to graft cultivated roses. Later, it was promoted for various other uses, including erosion control, wildlife food, and as live fencing for livestock.
Birds and small mammals spread the seeds. It occurs all over Missouri, primarily in pastures and fencerows, but also in open to partially shaded areas where soil has been disturbed. Its sprawling tendency allows it to form impenetrable thickets that smother other vegetation.
Musk Thistle Carduus nutans
Although native to Europe, musk thistle is widely established in the U.S. and occurs over most of Missouri. It grows primarily in pastures and old fields, on waste ground and along highway and railroad rights-of-way. It can also invade natural landscapes, including glades and prairies.
Musk thistle is prolific in open areas, producing as many as 11,000 seeds per plant. Infestations hurt farmers because the plant competes with crops for light, space, nutrients and water. Its spiny tissue is unsuitable for grazing livestock.
Purple Loosestrife Lythrum salicaria
This perennial plant was brought from Europe and Asia in the 1800s for use as an ornamental and as a nectar source for honeybees.
Purple loosestrife is designated a Missouri noxious weed, but some cultivars are still legal to sell. It has the ability to dominate freshwater marshes, wet prairies and other wetland habitats, eliminating native wetland flora. It thrives in full sun, where a single plant can produce 300,000 tiny seeds in a season. In mid to late summer, the showy purple spikes can be seen along ditches, pond and river banks, and in low, wet areas of fields.
Sericea Lespedeza Lespedeza cuneata
This perennial legume was brought to the U.S. from eastern Asia and has grown in Missouri since the 1930s.
Because it is drought-resistant and forms dense stands on steep slopes, it has been widely planted for erosion control. It's been used on private lands to stabilize soils along roads and pond levees. It was also promoted as a way to provide food and cover for wildlife.
Sericea lespedeza forms dense stands along many highways, producing seeds that are viable for 20 years or more. In Missouri, this plant has detrimental effects on prairies, glades, savannas and gravel bars. It spreads quickly in open range lands where it is not as palatable to livestock as native species.
Sweet Clover Melilotus alba and Melilotus officinalis
White and yellow sweet clover are legumes native to Europe and Asia but were recorded in North America as early as the 1600s. They have been planted as a forage crop, soil builder and wildlife cover crop, as well as for honey production. In Missouri, sweet clover grows along roadsides and railroads, fallow fields and pastures. It can spread into any unflooded, open natural habitat, such as a prairie.
Wintercreeper Euonymus fortunei
This evergreen, woody vine was brought to the U.S. from Asia for use as an ornamental groundcover. It is still planted for that purpose and is commonly found in forests near urban areas. Birds eating the fruits probably help the plants spread. Wintercreeper will climb on rocks and trees, and it will also form a dense ground cover. It can eliminate the spring wildflowers that would otherwise grow on the forest floor.