Desfontainia is a genus of flowering plants in the family Columelliaceae, though it was placed formerly in Loganiaceae, Potaliaceae, or a family of its own, Desfontainiaceae.

The Loganiaceae are a family of flowering plants classified in order Gentianales. The family includes up to 13 genera, distributed around the world's tropics. There are not any great morphological characteristics to distinguish these taxa from others in the order Gentianales.