Homalanthus is a genus of plants in the family Euphorbiaceae, first described in 1824. It is the only genus in the subtribe Carumbiinae. It is native to mainland Southeast Asia, Malesia, Papuasia, northern and eastern Australia, and various islands in the Pacific.

When published, the generic name was spelt as Omalanthus. Since the name comes from the ancient Greek word homalos meaning 'smooth' and anthos meaning 'flower', this original spelling was inconsistent with the general Greek transliteration rules, and many later authors changed it to Homalanthus. According to the International Code of Nomenclature for algae, fungi, and plants, Homalanthus has now been conserved against the original Omalanthus.

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