Dendrobium Kingianum

''Dendrobium kingianum'', commonly known as the pink rock orchid, is a flowering plant in the orchid family Orchidaceae and is endemic to eastern Australia. It usually grows on rocks, rarely as an epiphyte, and has thin, spreading leaves and spikes of up to fifteen, usually pink flowers in late winter to spring. It is popular in Australian native horticulture and is a commonly cultivated orchid among Australian orchid species growers.

Description

''Dendrobium kingianum'' is usually a lithophyte but is occasionally an epiphytic or rarely a terrestrial plant. Within its natural range, it grows on boulders and in rock crevices in open forest or adjacent to forest creeks. It can also be found on cliff faces. It sometimes occurs as an individual plant but can also form large colonies several metres across. Spongy, white roots enable it to absorb water quickly from a wet rock surface whilst at other times, reflect light to avoid overheating during long dry spells. The stems or pseudobulbs may be erect or spreading but are always succulent, serving as a water storage organ during dry periods. The roots emerge from the thicker base end of the pseudobulb, which tapers towards the tip. The pseudobulbs are long and in diameter and have between three and six leaves near the tip. The leaves are thin, green and smooth, folded along the mid-line, narrow egg-shaped and long and wide."Botanica. The Illustrated AZ of over 10000 garden plants and how to cultivate them", pp. 295-296. Könemann, 2004.

The flowers are arranged on a raceme long, with between two and fifteen flowers. The sepals and petals are usually pink but may be pure white, dark purple or a range of intermediate colours. The dorsal sepal is long, wide and the labellum is and wide, usually with dark purple marks. Flowering mostly occurs from August to October (late winter to mid-spring in the southern hemisphere), but can occur earlier or later in response to climatic cues.

Taxonomy and naming

''Dendrobium kingianum'' was first formally described by John Bidwill and his manuscript was published in ''The Botanical Register'', edited by John Lindley. In 2002, Mark Clements and David Jones proposed reassignment of ''Dendrobium kingianum'' to the genus ''Thelychiton'' (as ''Thelychiton kingianus''). The reassignment has not yet been accepted by the World Checklist of Selected Plant Families. Time and further research will determine whether ''Thelychiton kingianus'' is formally recognised. The specific epithet (''kingianum'') honours Admiral Phillip Parker King, RN, an early explorer of Australia’s southern and western coast.

Distribution and habitat

Pink rock orchid occurs from the coast to nearby ranges between the Hunter River in New South Wales and Rockhampton in Queensland where it usually grows on rock in forest and woodland.

Use in horticulture

Pink rock orchid is popular in Australian species orchid cultivation and is relatively easy to grow. It can successfully be grown on bark, fixed onto rock, or in a fast-draining medium of coarse bark and river pebbles. It grows best in a warm, sunny position and prefers relatively high humidity during its growing period of August to March. It is adapted to Australia’s dry east coast winters, and flowers best after a period of dry dormancy. It is available from specialist orchid nurseries but, like many Australian native plants, it is illegal to collect specimens growing in the wild.

Image:Dendrobium kingianum file picture.jpg
Image:Dendrobium kingianum (leaves and flowers).jpg, ''D. kingianum'' leaves and flowers
Image:Dendrobium kingianum (habit).jpg, ''D. kingianum'' growing near Coffs Harbour
Image:Dendrobium kingianum var. album GotBot 2015 002.jpg, An alba form in Gothenburg Botanical Garden

References

External links

American Orchid Society: Collector's Item: ''Dendrobium kingianum'' Bidwill ex Lindl.Massachusetts Orchid Society, Culture of ''Dendrobium kingianum'' By Dr. Wilford Neptune Santa Barbara (California) Orchid Estate, ''Dendrobium kingianum''
* ttps://web.archive.org/web/20130917192712/http://larchhillorchids.com/dendrobium_kingianum.html Larch Hill Orchids, Amherst Orchid Society, Amherst Massachusetts USA, ''Dendrobium kingianum''

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kingianum
Endemic orchids of Australia
Orchids of New South Wales
Orchids of Queensland
Plants described in 1844