Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Swainsonpea, Extension, University of Nevada, Reno, Field Guide

Stem

Up to 5 ft. tall and covered with short hairs

Leaves

Pinnate-compound; leaflets are oval, opposite, 0.2-0.8 in. long, lack leaf stems (petioles) and covered with short hairs on lower surface

Flower

Pea-like, reddish-orange and 0.5 in. long
Pods are oval, bladder-like, translucent and contain many seeds; seeds remain in pods during dispersal

Root

Woody, creeping root system; roots associate with nitrogen-fixing bacteria

Photo of Swainsonpea plant with small pink flowers

Other

Often infests roadsides, fencerows and irrigation ditches; not known to occur in Nevada
Perennial; reproduces by seed and creeping roots
Potential contaminant of alfalfa seed due to similar size, shape and weight
Also known as Austrian peaweed

Control

Hand removal of individual plants, including roots, can limit spread of small infestations
Apply 2,4-D, aminopyralid, clopyralid, dicamba, glyphosate, picloram, or triclopyr at bloom stage

Learn more about the author(s)

Staci Emm

Noah Scott

Also of Interest:


A Northern Nevada Homeowner's Guide to Identifying and Managing: Harvester Ants Harvester ants have large ant hill that are capable of reaching 12 feet in diameter and 3 feet deep. Harvester ants only become aggressive when disturbed and are capable of stinking. They do no invade homes, but are pests of lawns and gardens. Andrews, M., Hanson Mazet, W., and Kratsch, H. 2023, Extension, University of Nevada, Reno, FS-23-32

Nevada Noxious Weed Field Guide – Swainsonpea