Dendrobium mirbelianum, commonly known as the dark-stemmed antler orchid[1] or mangrove orchid, is an epiphytic or lithophytic orchid in the family Orchidaceae. It has cylindrical, dark-coloured pseudobulbs with leathery, dark green leaves and up to twelve pale to dark brown flowers with a yellow labellum with dark red veins. This antler orchid occurs in northern Australia, New Guinea and Indonesia.
Dendrobium mirbelianum is an epiphytic or lithophytic herb with cylindrical, dark blackish brown pseudobulbs NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide and is leafy in its upper half. The leaves are dark green, tinged with brown or dark red, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=2NaNsigfig=2 wide. The flowering stem is NaNsigfig=1NaNsigfig=1 long and bears between four and twelve pale to dark brown flowers NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide. The sepals and petals are sometimes twisted and sometimes remain closed, NaNsigfig=2NaNsigfig=2 long, and NaNsigfig=2NaNsigfig=2 wide. The labellum is yellow with red veins, about 30sigfig=1NaNsigfig=1 long and 20sigfig=1NaNsigfig=1 wide with three lobes. The side lobes curve upwards and the middle lobe has wavy edges and three ridges along its midline. Flowering occurs mainly from August to November but sporadically in other months. Some plants have widely opening flowers and are insect pollinated while others are self-pollinated and open slowly or not at all.[2] [3] [4]
Dendrobium mirbelianum was first formally described in 1829 by Charles Gaudichaud-Beaupré in his Voyage Autour du Monde ... sur les Corvettes de S.M. l'Uranie et la Physicienne.[5] [6] The specific epithet (mirbelianum) honours the French botanist and politician Charles-François Brisseau de Mirbel.
The dark-stemmed antler orchid grows in trees, especially mangroves, in coastal swamps and sometimes on rocks. It occurs on the Maluku Island in Indonesia, in New Guinea including the Bismark Archipelago, the Solomon Islands and on Moa Island and between the Daintree and Innisfail in Queensland.
This orchid is classed as "endangered" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and under the Queensland Government Nature Conservation Act 1992. The main threat to the species is land clearing for agriculture.[7]