Beginning in late May to early June, the plant produces up to 100 small, inward-facing pinkish to deep red and cream coloured flowers 4–5 mm (0.16–0.20 in) wide, surrounded by six to twelve pinkish-cream bracts.
[7] Rhizanthella gardneri was first formally described in 1928 by Richard Sanders Rogers in the Journal of the Royal Society of Western Australia from specimens collected near Corrigin in May of the same year.
[8] The specific epithet (gardneri) honours Charles Gardner, assistant botanist to the Western Australian Government at that time.
[9] Rhizanthella gardneri is only known from the Avon Wheatbelt biogeographic region of Western Australia, where it grows in association with broom honeymyrtle (Melaleuca uncinata), between Corrigin and Babakin.
The orchid obtains its energy and nutrients as a myco-heterotroph via mycorrhizal fungi that form associations with the roots of broombush species including M. uncinata, M. scalena and M.
[5] Three of the known populations of Rhizanthella gardneri are protected within nature reserves,[3] and a concerted initiative has been launched to safeguard this species for future generations.