Baileyoxylon is a monotypic genus in the family Achariaceae. The sole described species is Baileyoxylon lanceolatum which is restricted to a very small part of the Wet Tropics of Queensland. It was described in the mid 20th century.
Baileyoxylon lanceolatum is an evergreen tree growing up to about tall with medium grey bark and branchlets that are covered in rusty brown hairs. The dark green leaves are rather thick and measure up to long by wide, with 7–10 pairs of secondary veins either side of the midrib. They are obovate to oblong in shape, acuminate (pointed) at the tip and cuneate (tapering) at the base, and they have a relatively long petiole.
The much-branched inflorescence can reach up to long and is also covered with rusty brown hairs. The small flowers are about long and have 5 petals. The globose orange fruit is, in botanical terminology, a berry containing one or two seeds. It measures around diameter.
This species was first described in 1940 by the Australian botanist Cyril Tenison White, based on material collected by the botanical collector S. F. Kajewski from two individual trees in 1929. White's paper, titled "A new genus of Flacourtiaceae (Pangieae — Hydnocarpinae) from tropical Queensland", was published in the Journal of the Arnold Arboretum in January 1941.
The genus name Baileyoxlon was created by White in honour of the American botanist Irving Widmer Bailey, who provided much assistance to White in identifying the taxonomic placement of this new species.
The natural range of Baileyoxylon lanceolatum is a small area of upland rainforest on the eastern part of the Atherton Tableland, in the vicinity of Mount Bartle Frere. The total area of occupancy is just . The habitat is very wet mesophyll vine forest.
This species is listed by the Queensland Department of Environment and Science as least concern., it has not been assessed by the International Union for Conservation of Nature (IUCN).