5; see text Tetrathylacium is a genus of flowering plants in the family Salicaceae.

Previously it was treated in the family Flacourtiaceae[1] but was moved along with its close relatives to the Salicaceae based on analyses of DNA data.

[2] Tetrathylacium is rather unique in the Samydaceae in having tightly arranged panicles of spikes, four sepals and stamens, and non-arillate seeds.

[3] The stems are often inhabited by ants, and T. macrophyllum is suspected to have locust pollination.

The following species are accepted by Plants of the World Online:[5] This Salicaceae article is a stub.