In Clematis , leaves are opposite, simple or compound, and twining. Female flowers become a cluster of achenes, each bearing a long, plumose awn derived from the style. Attach to host plants by haustoria. Leaves reduced to minute scales. Flowers are small, regular and bisexual.
Fruit is a berry or drupe.
The stems are often quadrangular in cross-section with simple, opposite, or occasionally whorled leaves. Inflorescences usually axillary cymose clusters. Fruit splits into 4 achene-like nutlets.