Camelthorn

Alhagi maurorum

WA B desig. Fabaceae
Data Maturity Baseline

Washington State Classification

Class B — Control Required (Designated)

Camelthorn is unpalatable and injurious to some animals.

Required control in Region 1 (all western Washington counties)

Quick Reference

Type
shrub
Origin
Asia and Eastern Europe

Identification

Growth Habit

Camelthorn is a deep-rooted, rhizomatous, perennial shrub, with roots that can extend 6 to 7 feet into the ground. It is intricately-branched with spines and grows to 4 feet in height. It has pinkish purple to maroon flowers that bloom in the summer.

Leaves

Leaves are alternately arranged, grayish green and have smooth (entire) margins. They are oval to lance-shaped (much longer than wide with the widest part of the leaf below the middle).

Flowers

Flowers are pea-like and pinkish-purple to maroon. They are produced in clusters of 1 to 8 and are grouped toward the tips on spines or branchlets with spine tips.

Fruit & Seeds

Reddish-brown to tan seed pods are constricted between seeds and have a short, narrow beak at the end.

Impact

Camelthorn is unpalatable and injurious to some animals. Because of its deep root system, it grows successfully in dry, rocky, saline soil, making it weedy in rangeland, competing against preferred forage. It is also a potential alfalfa seed contaminant.

Ecology & Spread

Habitat

Camelthorn mainly grows in deep moist soil, but it also occurs in dry, rocky, or saline soils. The plant is especially abundant along riverbanks, canals and irrigation ditches, but it can also spread into cultivated fields. Please click here to see a county level distribution map of camelthorn in Washington.

Spread Mechanisms

seed vegetative fragments

Reproduction

Camelthorn reproduces by seed and rhizomes. Rhizomes can produce shoots 25 feet away from parent plant.

Regional Notes — Puget Sound

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Control Methods

Mechanical

  • If mechanical control is used, all rhizomes need to be removed to prevent fragments left in soil from re-sprouting.