''Dendrobium mirbelianum'', commonly known as the dark-stemmed antler orchid or mangrove orchid, is an

epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

lithophytic Lithophytes are plants that grow in or on rocks. They can be classified as either epilithic (or epipetric) or endolithic; epilithic lithophytes grow on the surfaces of rocks, while endolithic lithophytes grow in the crevices of rocks (and are als ...

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowerin ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Orchidaceae. It has cylindrical, dark-coloured

pseudobulb The pseudobulb is a storage organ found in many epiphytic and terrestrial sympodial orchids. It is derived from a thickening of the part of a stem between leaf nodes and may be composed of just one internode or several, termed heteroblastic and ...

s 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 New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...

and Indonesia.

Description

''Dendrobium mirbelianum'' is an epiphytic or lithophytic herb with cylindrical, dark blackish brown pseudobulbs long and wide and is leafy in its upper half. The leaves are dark green, tinged with brown or dark red, long and wide. The flowering stem is long and bears between four and twelve pale to dark brown flowers long and wide. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s and

petals Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usually ...

are sometimes twisted and sometimes remain closed, long, and wide. The labellum is yellow with red veins, about long and 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.

Taxonomy and naming

''Dendrobium mirbelianum'' was first formally described in 1829 by

Charles Gaudichaud-Beaupré Charles Gaudichaud-Beaupré (September 4, 1789 – January 16, 1854) was a French botanist. Biography Gaudichaud was born in Angoulême, to J-J. Gaudichaud and Rose (Mallat) Gaudichaud. He studied pharmacology informally at Cognac and Angoulême, ...

in his ''Voyage Autour du Monde ... sur les Corvettes de S.M. l'Uranie et la Physicienne''. The specific epithet (''mirbelianum'') honours the French botanist and politician

Charles-François Brisseau de Mirbel Charles-François Brisseau de Mirbel (27 March 1776 – 12 September 1854) was a French botanist and politician. He was a founder of the science of plant cytology. A native Parisian, at the age of twenty, he became an assistant-naturalist with ...

Distribution and habitat

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 Bismarck Archipelago (, ) is a group of islands off the northeastern coast of New Guinea in the western Pacific Ocean and is part of the Islands Region of Papua New Guinea. Its area is about 50,000 square km. History The first inhabitants o ...

, the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capit ...

and on

Moa Island Moa Island, also called Banks Island, is an island of the Torres Strait Islands archipelago that is located north of Thursday Island, Queensland, Thursday Island in the Banks Channel of Torres Strait, Queensland, Australia. It is also a Subur ...

and between the Daintree and Innisfail in

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

Conservation

This orchid is classed as "endangered" under the Australian Government

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cult ...

and under the Queensland Government

Nature Conservation Act 1992 The ''Nature Conservation Act 1992'' is an act of the Parliament of Queensland, Australia, that, together with subordinate legislation, provides for the legislative protection of Queensland's threatened biota. As originally published, it pro ...

. The main threat to the species is land clearing for agriculture.

References

{{Taxonbar, from=Q15458064 mirbelianum Orchids of Indonesia Orchids of New Guinea Orchids of Queensland Plants described in 1829 Taxa named by Charles Gaudichaud-Beaupré