Common Name: False Indigo
Specific Name: Amorpha fruiticosa
Known Occurrence at Taylor Point:
Map Areas: Bridge 4B
Category: Invasive, Non-Native, Shrub
Ecological Considerations:
Amorpha fruiticosa is a medium-sized shrub that can grow up to about 10 feet tall. Its branches are firm and woody. Its twigs are green and hairy. The leaflets are 1 to 2 inches long, resinous, dotted and hairy. In New England it usually grows somewhat lower. It has distinctive violet flowers that appear as upright narrow racemes in June and July. Its fruits remain on the plant through winter.
This shrub is typically found alongside rivers, in flood plains, and in tidal zones. It also grows in moist open woods and alongside highways. Amorpha fruticosa is salt-tolerant and tolerates nutritionally poor soils, owing to its association with nitrogen fixing bacteria. False indigo thrives in full sun or light shade, and in moist soils that are poorly drained. It can also grow well on silt loams and even dry sands.
False Indigo can serve as effective erosion control along shorelines because it becomes established quickly.
Problems Posed by this Plant:
Amorpha fruiticosa is known to out-compete native species, especially along waterways above the high water line.
Native Species Affected by this Plant:
Factors Affording a Competitive Advantage to this Plant: False indigo grows quickly, can form dense thickets, and is highly adaptable.
Propagation Mechanisms and Related Issues Affecting Efforts to Remove and/or Eliminate this Plant from Taylor Point:
Amorpha fruticosa is pollinated primary by bees. It propagates by seed. Waterways may play a role in seed dispersal.
Documented Best Removal Practices and Options/Pros and Cons of Various Options:
Case Studies of Removal Efforts, Lessons Learned and Recommendations:
Sources cited:
Invasive Plant Atlas of New England
State of Washington, Department of Ecology
Invasive Plant Atlas of the United States
Key Words:
Shrub
False Indigo
Amorpha fruiticosa
Bridge
4B