Rhizanthella, commonly known as underground orchids, is a genus of flowering plants in the orchid family, Orchidaceae and is endemic to Australia. All are leafless, living underground in symbiosis with mycorrhizal fungi. The inflorescence is a head of flowers held at, or just above the ground but mostly covered by soil or leaf litter and little is known about the mechanism of pollination.

Rhizanthella gardneri, commonly known as western underground orchid, is a species of flowering plant in the orchid family and is endemic to the southwest of Western Australia. It is a herb that spends its entire life cycle, including flowering, at or below the soil surface. A head of up to 100 small reddish to cream-coloured, inward facing flowers surrounded by large, cream-coloured bracts with a horizontal rhizome is produced between May and July.