About Indigofera incarnata (Willd.) Nakai
Indigofera incarnata (Willd.) Nakai (also referred to as Indigofera decora) is a species of shrub in the Fabaceae family, genus Indigofera. It is commonly known as summer wisteria. This shrub is native to China and Japan, and has been introduced to Australia and Sri Lanka. It is primarily used for decorative purposes, and has also been used to produce indigo-colored dye. Indigofera decora is a deciduous, spreading shrub that typically reaches 1 to 2.5 feet in height and 3 to 4 feet in width. It bears compound, pinnate leaves that can grow up to 8 inches long, with 7 to 13 elliptic, dark green leaflets. In summer, it produces axillary racemes of light pink or purple, pea-shaped flowers. Each raceme holds 20 to 40 flowers, and its calyxes have broadly triangular lobes. This species grows best in well-drained, neutral to slightly alkaline soils. It has moderate tolerance to heat and drought, but benefits from afternoon shade in hot, humid climates. It is cold hardy in USDA zones 7 to 11 in the United States.
