Habenaria ferdinandi, commonly known as the yellow rein orchid, is a species of orchid that is endemic to the Northern Territory. It usually has two leaves at its base and up to fifteen tiny yellowish green, strongly scented flowers.
Habenaria ferdinandi is a tuberous, perennial herb usually with two upright, dark green leaves at its base, the leaves NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Between seven and fifteen yellowish green, strongly scented flowers, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=2NaNsigfig=2 wide are borne on a flowering stem NaNsigfig=1NaNsigfig=1 tall. The dorsal sepal is about 3sigfig=2NaNsigfig=2 long and 2sigfig=1NaNsigfig=1 wide, overlapping with the base of the petals to form a hood over the column. The lateral sepals are 4sigfig=2NaNsigfig=2 long, 2sigfig=1NaNsigfig=1 wide and spread widely apart close to horizontally. The petals are about 2sigfig=1NaNsigfig=1 long and 1.5sigfig=1NaNsigfig=1 wide. The labellum is about 3sigfig=1NaNsigfig=1 long, 6sigfig=1NaNsigfig=1 wide and has three lobes. The side lobes are thread-like, about 4.5sigfig=1NaNsigfig=1 long with erect tips and are held at about 90° to the middle lobe which turns downwards and is about 3.5sigfig=1NaNsigfig=1 long. The nectary spur is about 5sigfig=1NaNsigfig=1 long and held parallel to the ovary. Flowering occurs from December to March.[1]
Habenaria ferdinandi was first formally described in 1911 by Rudolf Schlechter, although he initially gave it the name Habenaria muelleriana, an illegitimate name because it had been used for a different species by Alfred Cogniaux.[2] The original[3] and the correction[4] were published in Repertorium Specierum Novarum Regni Vegetabilis.[5] The specific epithet (ferdinandi) honours the botanist Ferdinand von Mueller.[6]
The yellow rein orchid is found in northern parts of the Northern Territory where it grows in grassy forest and at the base of sandstone escarpments.[7]