Scleromitrion diffusum, synonyms including Hedyotis diffusa, is a species of flowering plant in the family Rubiaceae.

In the sense used in the Flora of China, and in much research on the phytochemistry, pharmacology and potential medical applications of the species, Hedyotis diffusa refers to a plant with solitary-flowered (or at most two- or three-flowered) inflorescences.

In 2021, it was proposed that the name Hedyotis diffusa should be conserved, based on a one-flowered specimen as the type.

[4] These are the homotypic synonyms accepted by Plants of the World Online as of March 2023[update], which treated the taxon as Scleromitrion diffusum.

[1] Wild Scleromitrion diffusum is native to tropical and subtropical Asia.