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Everlasting Pea

Lathyrus sylvestris (LATH-ih-rus sil-VESS-tris)

Family: Fabaceae Non-native Vine (vertical)

The Flat Pea is a long-lived, herbaceous perennial, flowering vine in the bean family with a scrambling habit. The plant is native to Great Britain and Europe west to Siberia and has been introduced into Canada and the northern United States, although it can be found as far south as Georgia. The plant has a winged stem, narrow green leaves, purple pea-like flowers in elongated clusters that bloom in early summer, and a flattened pod. It will climb to a height of 7 feet if supported or grow to height of 30 inches without support. Once established, he plants will often form a mat as they spread by rhizomes, and it can become weedy or invasive and prevent the establishment of other plants if not properly managed. The Flat Pea does best in well-drained soil and full sun to partial shade. The Flat Pea tolerates most soil types, even severely disturbed, acidic, soil and is drought tolerant. Once established, the plant requires little in the way of maintenance. It is edible in small quantities; however, when eaten in large quantities, it can cause a serious disease of the nervous system known as 'lathyrism'. It also contains an acid that can be toxic to livestock not acclimated to it. Flat Pea requires the incorporation of the seed into the soil for propagation; broadcasting the seed will not succeed unless the seed is subsequently covered with soil. It is also best to plant Flat Pea with a grass, such as tall fescue, to provide cover over the 2 to 3 years needed to establish itself. As a vine, the Flat Pea can spread up to 79 inches and will cling to any supporting structure with tendrils. Like most pea plants, the Flat Pea will fix nitrogen in the soil. The Flat Pea is found on embankments and waste ground where it uses its tendrils to scramble over plants, shrubs and the lower branches of trees. This trait, plus its tolerance of poor and acidic soil, makes it useful in erosion control and efforts to improve marginal soil. Diseases, Insect Pests, and Other Plant Problems: No known diseases or insect pests. The plant can spread easily and can become weedy. More information on Lathyrus .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 61 attributes.

How it fits the guild

Guild layer 6 - Vine (vertical) Optimal soil pH Acid (<6.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Full plant profile

Growing Conditions
Plant type
Ground Cover; Herbaceous Perennial; Poisonous; Vine
Life cycle
Perennial
USDA zones
2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; High Organic Matter; Loam (Silt); Sand; Shallow Rocky
Soil pH
Acid (<6.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Occasionally Dry
NC region
Coastal; Mountains; Piedmont
Growth rate
Medium
Maintenance
Low
Canopy layer
6 - Vine (vertical)
Form & Appearance
Habit / form
Climbing; Creeping; Spreading
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Alternate
Leaf margin
Entire
Hairs present
No
Leaf detail
The narrow green leaves are alternate, pinnately divided, and each leaf has 2 or more leaflets and a terminal tendril.
Flower color
Pink; Purple/Lavender
Flower shape
Bell
Flower size
< 1 inch
Flower detail
A long stem supports three to ten pinkish-red flowers. The flowers have five sepals and five petals and are irregular. There are ten stamens and a single carpel.
Bloom time
Summer
Fruit color
Black
Fruit type
Legume
Fruit value
Edible
Fruit size
1-3 inches long
Fruit detail
Flattened two inch pod containing 5 to 15 seeds.
Stem color
Green
Stem detail
Floppy and flat with wide wings of leaf-like appendages.
Wildlife & Ecology
Native status
Non-native
Origin
Europe to Western Siberia and Caucasus
Distribution
Introduced to Eastern Canada the northern United States.
Wildlife value
Birds feed on the seeds.
Food & Medicine
Edible parts
Fruit
Harvest time
Summer
Fruit type
Legume

Edibility

Moderately toxic if consumed in large quantities.

Uses (ethnobotany)

Flat Peas is an effective erosion control plant.

Landscape Use
Landscape location
Rock Wall; Slope/Bank
Landscape theme
Drought Tolerant Garden
Design feature
Border; Mass Planting
Garden tags
#poisonous #vine #erosion control #groundcover #flowering vine #spreading #drought tolerant #acidic soils tolerant #weedy vine #low maintenance #mat forming #poor soil tolerant
Problems & Resistance
Problems
Poisonous to Humans; Weedy
Resistant to
Drought; Poor Soil
Particularly resistant to
drought, acidic soil.
Propagation
Seed
Poison severity
Medium
Poison parts
Seeds
Poison symptoms
Toxic to humans if eaten in large quantities. Toxic to livestock not acclimated to diaminobutyric acid. Symptoms can include paralysis, slow and weak pulse, shallow breathing, and convulsions.
Toxic principle
diaminobutyric acid (DABA)
Contact dermatitis
No
Toxicity summary
Medium severity poison; parts: Seeds

Planted at Hunnicutt

Nobody’s planted this one yet.