Euphorbia tannensis is a species of herb or shrub native to Australia and some Pacific islands.
It grows as an erect annual or perennial herb or shrub, from 10 centimetres to a metre in height, with green or yellow flowers. It often appears spindly due to its leaves being deciduous.[1]
This species was first published by Curt Polycarp Joachim Sprengel in 1809, based on a specimen collected by Georg Forster in . In 1977 two species, E. eremophila and E. finlaysonii, were submerged within E. tannensis as E. tannensis var. eremophila and E. tannensis var. finlaysonii respectively, these being treated as varieties of a new subspecies, E. tannensis subsp. eremophila.[1]
This species is widespread on the Australian mainland, occurring in every mainland state, though only in the far north-west corner of Victoria (Australia).[1] It is widely reported as occurring only in Australia; yet the type specimen was collected on Tanna in what is now Vanuatu, and it has also been recorded in New Caledonia.[2]