Amorpha fruticosa (Indigo Bush, False Indigo, Desert Indigo, Leadplant, Bastard Indigo, River Locust, False Indigo Bush, Desrt False Indigo)


Botanical Information

FamilyFabaceae
GenusAmorpha
Speciesfruticosa
SynonymsAmorpha croceolanata
CategoryWoody
TypeShrub (deciduous)
ReferencesDirr, M. (2009). Manual of Woody Landscape Plants Their Identification, Ornamental Characteristics, Culture, Propagation and Uses. Champaign, Illinois: Stipes Publishing L.L.C. USDA NRCS National Plant Data Center. (2006) Plant Guide for Desert False Indigo Amorpha fruitcosa L. Washington D.C.: USDA
OriginNative to the United States of America predominantly in the central regions of the country but can be found as far South as California. Native in Manitoba, Canada but has been introduced into Ontario and Quebec.
Ethnobotanical Uses
Disclaimer
Resin used as an insect repellant.

Details

USDA Hardiness Zone4 - 9
USDA Hardiness Ref.
Canadian Hardiness Zone3a - 4a
Canada Hardiness Ref.
RHS Hardiness ZoneH7
RHS Hardiness Ref.
Temperature (°C)-20
Temperature (°F)-4
Height1 - 4 m
Spread2 - 5 m
GrowthFast
Flowering PeriodJune, July

Description and Growing Information

ShapeAn arching shape.
LandscapeThis plant can be used as an ornamental plant and as a windbreak.
PropagationScarification must occur. This can be done with sulfuric acid for 5 - 8 minutes or with tumble scarification for 2 - 3 hours. Also a hot water treatment with 5 - 10 grams of seed in 100 ml of 90°C water and let stand for 1 hour. Cutting from softwood stems can also be rooted, take cutting June/July and plant in peat moss, perlite growing media and keep moist, this method has a success rate of roughly 90%.
CultivationHighly adaptable to soil pH and does well in poor, dry, sandy soils and full sun.
PestsRust fungi (Uropyxis amorphae), leaf spots, powdery mildew and twig canker.
Notable SpecimensThe University of Alberta Botanic Garden, Edmonton, Alberta, Canada.
HabitatWetlands and along river banks.
Bark/Stem DescriptionScattered small lenticels.
Flower/Leaf Bud DescriptionImbricate, often superposed, essentially glabrous and appressed.
Leaf DescriptionAlternate, pinnately compound leaves with a varying amount of leaflets of 13 - 33, can be oval or elliptic with a size of 1.2 - 3.8 cm long and 0.6 - 1.2 cm wide. Mucronate at apex, rounded at ends, finely pubescent and glabrate; short thread-like stipule at the base of each leaflet.
Flower DescriptionConsists of one petal and is 0.8 cm long on 7.5 - 15 cm upright spikes
Fruit DescriptionSmall 0.8 cm long kidney-shaped pod covered in stipules.
Colour DescriptionLeaves green in summer turning to yellow in autumn. Flowers are indigo containing orange anthers. An early hard freeze will turn foliage brown. The stems are green when young and turn to a brownish-grey with maturity.
Texture DescriptionBark is smooth.

Photographs