One characteristic that distinguishes Smilacaceae from most of the other members of the Liliaceae-like Liliales is that it has true vessels in its conducting tissue.

Members of this family typically have woody roots and a climbing or vining form.

The flower of Heterosmilax is fused into a deep bottle-shaped tube containing prominent nectaries and its stamens are connected at the bottom, whereas flowers of Smilax are typically small with unfused floral parts.

Heterosmilax has only twelve species which are confined to China, Japan, tropical Asia, Singapore, Malaysia, and the surrounding islands.

Some taxonomists separate the herbaceous plants native to North America in Smilax as the genus Nemexia, which is known for its malodorous flowers.

However, the Flora of North America does not recognise Nemexia, nor does the Missouri Botanical Garden's Angiosperm Phylogeny Website.