Characteristics
The dogbane family consists of trees, shrubs, herbs, or lianas, usually with milky sap. The leaves are simple, usually opposite and decussate, or whorled; lacking stipules. Flowers are usually showy, actinomorphic, aggregated in cymose or racemose inflorescences (rarely fasciculate or solitary). They are perfect (bisexual), with a synsepalous, five-lobed calyx united into a tube at the base. Inflorescences are terminal or axillary. Five petals are united into a tube with four or five epipetalous stamens. The style is expanded at the apex into a massive clavuncle just below the stigma. The ovary is usually superior, bicarpellary, and apocarpous, with a common fused style and stigma.
The fruit is a drupe, a berry, a capsule or a follicle.
Read more about this topic: Apocynaceae