Perennial Peavine

Lathyrus latifolius

Monitor List – Invasive Weed

General

Native to north temperate and subtropical zones of Europe and Asia.
There are more than 400 different English ivy cultivars, which vary in leaf shape, size, color and habit. There are four listed cultivars of English ivy which are derived from two species Hedera Hibernica and Hedera helix. These have the greatest invasive potential and should not be sold or purchased.
- Native plant alternatives include salal, low Oregon grape, and kinnikinnick.
Outcompetes native plants and inhibits regeneration of understory plants.
Kills overstory trees by shading out foliage and suppressing the host tree. As the tree begins to die the open crown allows for additional ivy growth, adding greater weight to the tree and increasing storm damage.
Changes the natural succession patterns of forests.
The sap of the stems can cause skin irritations and rashes to sensitive individuals.
Long lived, plant samples estimated to be greater than 400 years old. Vines can grow up to 99 feet long, with stems reaching one foot in diameter.

Identification

Sprawling or climbing perennial herbaceous vine.
Stems are hairless, broadly winged and grow 6 to 7 feet long. They can climb by means of tendrils; otherwise they sprawl across other plants or on the ground.
Leaves are blue-green, narrowly oval-shaped, compound occurring in pairs, with a winged petiole about 2 inches long. Leaves are smooth and hairless.
Pea-like flowers are an inch long and can be white, red or pink. Grow in clusters of 5 to 15 and are unscented. Flowers mid-June through September.
Seeds form in pods, are brown colored and 2/3 smaller than the common edible garden pea.

Photos

Habitat

Requires partial to full sun and a relatively dry soil.
Occupies a wide range of climactic conditions thriving in the warm wet environment of the Pacific Northwest to the cold dry conditions of the Rocky Mountain States.
Found mainly in disturbed sites. Aggressively grows along right-of-ways, seasonally dry meadows, forests and natural areas.

Reproduction and Spread

Above ground growth dies each winter and regrows each spring form deep roots.
Reproduces primarily through rhizomes but also by seed.
Vegetative reproduction via horizontal spreading rhizomes and the rooting of stem and rhizome fragments.
Mature seed pods twist and eject the seeds, which can fall up to 30 feet away from the parent plant.
Seeds are dispersed by human activities, water and animals.

Control

Prevent plants from spreading by washing equipment, vehicles, and boots that have been in infested areas.
Hand pulling or digging plants early before they flower, can be effective for small infestations. Make sure to remove the entire root system as plants will re-sprout from root fragments. Soil disturbance will likely cause germination of seeds already in the soil, so follow up monitoring and removal will be necessary.
Cutting or weed-whacking stems will remove above ground growth and can prevent plants from seeding. Plants will regrow from the roots so continual mowing will be necessary to eventually deplete the root reserves of the population.
Cutting followed by an application of herbicide to the regrowth is effective and will reduce the amount of herbicide used.
Cutting in combination with a biodegradable weed barrier such as burlap or cardboard and a thick layer of mulch may be effective; however Jefferson Noxious Weeds recommends not using mulch as weeds can grow in the mulch and the weed fabric makes removal more difficult.

Herbicide Control