Habenaria xanthantha, commonly known as the freak rein orchid, is a species of orchid that is endemic to far northern Queensland. It has two or three leaves at its base, and up to twenty small white flowers often lacking the nectary spur present on other species in the genus.
Habenaria xanthantha is a tuberous, perennial herb with two or three upright leaves, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Between eight and twenty white flowers, NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide are borne on a flowering stem NaNsigfig=1NaNsigfig=1 tall. The dorsal sepal is about 6sigfig=1NaNsigfig=1 long, 2.5sigfig=1NaNsigfig=1 wide and with the petals, forms a hood over the column. The lateral sepals are NaNsigfig=2NaNsigfig=2 long, about 3sigfig=1NaNsigfig=1 wide and spread apart from each other and turn downwards. The petals are similar in size to the lateral sepals. The labellum is NaNsigfig=1NaNsigfig=1 long, about 3sigfig=1NaNsigfig=1 wide and sometimes has three lobes. When present, the nectary spur is up to 2sigfig=1NaNsigfig=1 long. Flowering occurs from March to April.[1]
Habenaria xanthantha was first formally described in 1869 by Ferdinand von Mueller and the description was published in Fragmenta Phytographiae Australiae.[2] The specific epithet (xanthantha) is derived from the ancient Greek words meaning "yellow" and meaning "flower",[3] although no yellow-flowering forms have been seen in the last fifty years.
The freak rein orchid grows in moist to wet woodland on some Torres Strait Islands and on Cape York Peninsula south to Proserpine.