False indigo. A medium Sized North American shrub, growing to 3-4 m (10-13 ft) high. It is a nitrogen-fixing legume. The crushed seeds have been used as a condiment (though they may not be wholesome); resinous pustules on the plant contain an insecticidal compound effective against aphids and cattle flies. The plant contains small amounts of indigo pigment and can be used to make a blue dye. A good wildlife plant. Needs a well-drained soil and sun or light shade; hardy to -40°C. Stratification: CS2. Number of seeds: 50.
