Diuris semilunulata, commonly known as the late leopard orchid, is a species of orchid that is native to New South Wales and the Australian Capital Territory. It has two grass-like leaves and up to five orange-coloured flowers with brown and purple blotches.
Diuris semilunulata is a tuberous, perennial herb with two linear leaves, each NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and folded lengthwise. Between three and five orange-coloured flowers with large brown and purple blotches, NaNsigfig=1NaNsigfig=1 wide are borne on a flowering stem NaNsigfig=1NaNsigfig=1 tall. The dorsal sepal is erect, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and egg-shaped. The lateral sepals are linear to lance-shaped with the narrower end towards the base, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide, turned downwards or backwards and crossed over each other. The petals are curved backwards, broadly egg-shaped to almost circular, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide on a dark reddish brown stalk NaNsigfig=1NaNsigfig=1 long. The labellum is NaNsigfig=1NaNsigfig=1 long and has three lobes. The centre lobe is wedge-shaped, NaNsigfig=1NaNsigfig=1 wide with a central ridge. The side lobes are NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide. There are two raised callus ridges NaNsigfig=1NaNsigfig=1 long near the mid-line of the labellum. Flowering occurs from October to December.[1] [2]
Diuris semilunulata was first formally described in 1944 by Pearl Messmer and the description was published in Herman Rupp's book The Orchids of New South Wales.[3]
The late leopard orchid mostly grows in shallow, rocky soil in open forest in the Australian Capital Territy, New South Wales south from Nerriga and possibly Victoria.