Opopanax, also known as opobalsam, refers to a number of gum resins (natural substances that are a mixture of water-soluble gums and alcohol-soluble resins) traditionally considered to have medicinal properties. Pliny (Historia Naturalis) and Dioscorides (De Materia Medica) described various kinds with uncertain identifications, which have been distinguished as:

• A species of Centaurea
• Lovage (Levisticum officinale)
• Yarrow (Achillea millefolium)
• Echinophora tenuifolia (Umbelliferae)
• Ferula opopanax, also known as Opopanax chironium (Umbelliferae)
• Fig-leaved cow parsnip, Heracleum panaces (or other species of Heracleum)

In recent times, the main source of commercial opopanax is from species of Commiphora, particularly C. erythraea and C. kataf. (Some sources suggest the entire production is from C. erythraea var. glabrescens, a tree growing in Somalia.[6]) Myrrh is also obtained from Commiphora species.