Vicia americana

American vetch (native)

Fabaceae

North America (native) — Alaska to Mexico and coast to coast

Attracts Pollinators Attracts Butterflies Drought Tolerant

Native to North America

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 3–9

Overview

Vicia americana is a native perennial scrambling vine in the pea family (Fabaceae spp.) reaching 12–36 inches (30–90 cm) tall, climbing by branched terminal tendrils on leaf rachises. Stems are slender, angular, smooth to sparsely hairy. Leaves are alternate, pinnately compound, with 8–14 ovate to elliptic leaflets 0.4–1 inch (10–25 mm) long and a branched terminal tendril replacing the terminal leaflet. Stipules are small, arrow-shaped, toothed. Flowers are blue-purple to violet, 0.6–0.8 inch (15–20 mm) long, papilionaceous (pea-type), in racemes of 3–9 flowers on axillary peduncles. Fruit is a smooth flattened legume pod 0.8–1.4 inches (20–35 mm) long. Nitrogen-fixing via Rhizobium spp. root nodules. Native to North America and included in the weed-identification collection as the native reference species for comparison with three introduced Vicia spp. species (V. hirsuta, V. sativa, V. villosa). The species occurs in meadows, open forests, and roadsides throughout the Pacific Northwest.

Native Range

Vicia americana is native to North America from Alaska to Mexico and coast to coast, occurring in meadows, open forests, thickets, and roadsides from sea level to approximately 10,000 feet (3,000 m). The species is common in the Pacific Northwest at low to mid elevations. Included in the HORT 280 weeds collection as the native reference for the Vicia spp. genus comparison.

Suggested Uses

Used as the native reference in the four-species Vicia spp. identification exercise: native V. americana (pedunculate raceme, 3–9 blue-purple flowers, perennial) versus V. sativa (sessile, 1–2 reddish-purple, annual) versus V. villosa (dense woolly raceme, 10–30, annual or biennial) versus V. hirsuta (tiny flowers, 1–6, narrow-leaved annual). The native-versus-introduced comparison is a recurring theme in the weeds course. Nitrogen fixation via Rhizobium spp. is taught alongside Trifolium spp. and other Fabaceae spp..

How to Identify

Separated from Vicia sativa (common vetch) by a raceme of 3–9 flowers on a distinct peduncle (versus 1–2 flowers sessile in the leaf axils), blue-purple (versus reddish-purple) flowers, and native perennial habit (versus introduced annual). Separated from V. villosa (woolly vetch) by smooth (versus densely hairy) stems and fewer flowers per raceme (3–9 versus 10–30). Separated from V. hirsuta (tiny vetch) by much larger flowers (0.6–0.8 inch versus 0.08–0.16 inch) and fewer, larger leaflets.

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread1' - 3'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Flowers from May through July. Racemes of 3–9 flowers bloom over 3–4 weeks. Pollination is by bees. Pods mature 4–6 weeks after flowering, dehiscing to release 3–8 seeds. In the Pacific Northwest, peak bloom occurs in June.

Detailed Descriptions

Flower Description

Blue-purple to violet; papilionaceous; 0.6–0.8 inch (15–20 mm) long; in racemes of 3–9 flowers on axillary peduncles

Foliage Description

Medium green; pinnately compound with 8–14 ovate to elliptic leaflets and a branched terminal tendril

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam sand silt

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1 year

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

As a native species, V. americana is not typically managed as a weed. The species is included for identification reference. In restoration settings, it is valued for nitrogen fixation, wildlife forage, and pollinator support. In agricultural settings where it appears, it is managed similarly to other vetches. The perennial habit and rhizomatous spread separate it from the annual introduced vetches.

Pruning

Pruning is not applicable. As a native species, V. americana is typically retained or encouraged in natural areas. In cultivated settings, plants are pulled if unwanted.

✓ Toxicity

Non-toxic

Vines