1. Erythrina is a shrub or small tree of Vitex, with a height of 1-11 meters; The old branches are gray-white, lenticellate, and have a yellowish flaky diaphragm. The leaves are papery, ovate, ovoid-elliptic or triangular-ovate, the top is gradually pointed, the surface is dark green, the back is light green, the corymbose cymes are terminal or axillary, usually dichotomous, scattered, bracts are leaflike, elliptic and caducous; Calyx buds are green and white, then purplish red, and the lobes are triangular-lanceolate or ovate, with sharp tips; Flower fragrance, white or pinkish corolla, thin tube, filaments and styles sticking out of the corolla; Drupe is nearly spherical, and flowering and fruiting period: July-February.

2. Erythrina likes sunshine, slightly tolerant to shade and drought, barren, heat-resistant, cold-resistant, slightly tolerant to saline-alkali. Not strict with the soil, like to wet the soil, but not resistant to water accumulation.

3. The inflorescence of Erythrina purpurea is large and beautiful, and the flowers and fruits on a tree are white, red and blue, which can be described as colorful, and the flower and fruit period is long, and the viewing period can be as long as 6 months. It is a good flower and fruit viewing plant, and it is a common greening tree species in Europe.