The base is round or wide wedge-shaped, the edge is microwave-shaped, and the veins are 5 ~ 9. Flowers are solitary or arranged in cymes, and the total pedicel is completely attached to the midvein of leaves; Tepals 4, rolled outward after opening; Stamens have a short subulate appendage at the top of anthers. Capsule ovoid, slightly flattened. The seeds are dark purple and brown. The flowering period is April-May, and the fruiting period is July.