Clematis is a genus of about 300 species within the buttercup family Ranunculaceae. Their garden hybrids have been popular among gardeners; beginning with Clematis 'Jackmanii'; a garden standby since 1862. More hybrid cultivars are being produced constantly. They are mainly of Chinese and Japanese origin.

Most species are known as clematis in English; while some are also known as traveller's joy; a name invented for the sole British native; C. vitalba; by the herbalist John Gerard; virgin's bower for C. viticella; old man's beard; applied to several with prominent seedheads; and leather flower or vase vine for the North American Clematis viorna. Pictures From History