Fontainea fugax is a shrub endemic to Queensland, in the family, Euphorbiaceae, growing up to 4 m. In 1997, F. fugax was considered "endangered" having been found in only in the central Burnett district and within an endangered community, threatened by weeds, repeated fires and clearing.

[2] Fontainea fugax is a dioecious shrub growing to 4 m. The stems have a clear exudate.

[2] Fontainea fugax is known only from an area between Gayndah and Mundubbera, in south-east Queensland, with plants growing as understorey shrubs in a semi-evergreen vine thicket dominated by Backhousia kingii.

[2] The plant was first described by Paul Irwin Forster in "Three new species of Fontainea Heckel (Euphorbiaceae) from Australia and Papua New Guinea".

[1][2] The holotype AQ 650045 was collected on February 9, 1994, on the Gurgeena Plateau (Burnett district, Queensland) at a height of 360 m.[3] The specific epithet, fugax, derives from the Latin for "fleeting" and refers to the fleeting flowering material of this species, with female flowers not having been seen.