It used to be called Phaius tankervilleae, but that name (properly spelled tancarvilleae) is now reserved for its close genetic ancestor which is found from southeast Asia to the Himalayan foothills.  The name tancarvilleae comes from the town of Tancarville in northern France.  The plant was originally named by Joseph Banks in honour of Emma, Countess of Tankerville (the anglicised version of the name), who lived near London and who first flowered plants that had been collected from southern China in 1788.
Phaius australis has distinctively white (outer) and brownish (inner) petals and sepals and a purplish tubular labellum.  It typically produces sequentially opening flowers of about 100mm size with up to 20 flowers per inflorescence which may be up to 2m tall.  It has been recorded in the wild in eastern Australia from Cape York as far south as the Hunter River, and is currently identified in the wild from Cooktown to Taree.  It was recorded by Alan Cunningham in 1824 from a creek inland from Pumicestone Passage.
The closely-related Phaius bernaysii, with distinctive yellow-green and white colouration, is currently identified in the wild only on North Stradbroke Island.  Both have been ruthlessly collected in the past, and both have had their natural habitat severely altered and disrupted b
y coastal development.

Phaius australis


Also commonly known as the Swamp Orchid.

Scientific name:

Phaius australis

Conservation status in NSW: 

Endangered

National conservation status:

 
Endangered


Description


The swamp orchid, Phaius australis, is our Society’s emblem and was formerly widespread in the Sunshine Coast wetlands.  Neal and Ella Walker achieved an award for a plant at one of our recent spring shows.
Phaius australis, Phaius bernaysii, and Phaius tancarvilleae are all represented in local collections.  Unless its source location is known, specialist botanical knowledge and skills are required to positively identify a tame plant as Phaius australis rather than Phaius tancarvilleae.  Australian-sourced plants (australis and bernaysii) are genetically distinct from their Asian ancestor tancarvilleae.  There is no such genetic distinction between australis and bernaysii, and the latter is now regarded as an albino form of australis but is likely to retain its separate species name.
John Simmons (one of our club members) daughter - Laura Simmons undertook her University of Sunshine Coast PhD study of Phaius australis and Phaius bernaysii over the period 2011 to 2016.  Her records of its distribution and genetics provide essential knowledge for its conservation in the wild, and also provide us with guidance for successful culture of tame plants.
On the Atherton Tablelands, Phaius australis grows in open swamps, springs at rock layers, roadside drains: generally in open sunlight and permanently wet.  In Central Qld at the Blackdown Tableland, it grows in open or slightly shaded swamps and around springs where the ground is permanently wet.  At Carnarvon Gorge, it is found only in partial sunlight around springs at the base of cliffs and surrounded by palms and ferns, and there are only a few individuals.  On North Stradbroke Island it grows in coastal swamps surrounded by paperbarks, sedges, palms, and ferns.  Most sites are permanently wet, and there are lots of individuals.  Many plants were translocated from sand mining areas, but source records are sketchy at best.  In northern NSW it is found in coastal paperbark swamps and around cabbage tree palms, where conditions are mixed shade and sun.  There is a general tendency for it to be in more sheltered conditions in the southern part of its range.
From a conservation viewpoint, only about 50% of the historically recorded populations remain in the wild, with many of those being small.  Maintaining or increasing current wild population sizes is important for future conservation.  The plant is hardy and adaptable in the conditions for which it evolved.  Tame plants should never be translocated to the wild without prior confirmation that the source plant was endemic to the translocation site.  Its greatest threats are land development, wild plant removal, wild flower collection (which removes its capacity to propagate) and inappropriate management of controlled burns (which has recently happened to the one population still known in Noosa National Park).
Phaius australis is a large, tough, and vigorous plant consisting of trains of corms with no real ryzome.  Successful culture of tame plants requires close observation of its wild habits.  In the wild, its corms grow within rather than on the surrounding soil, with only their necks and leaves sticking out.  Flowering is in Spring from the lead corm of a train of at least three corms.  Subsequently the plant will grow one or more new corms with leaves while shedding its older leaves.
It needs access to fresh oxygenated water, dappled sunlight, and peaty but well-drained soil, and cannot withstand sustained temperatures lower than 6°.  Plants grow successfully under 50% green shadecloth or open dappled sunlight, and very airy open conditions.  They flower predictably with gay abandon when potted in a customised mixture of about 25% sand to 75% of typical good quality cymbidium mix.  Stand the pots in shallow saucers that will keep them wet.  Repot every 2-3 years to maintain good quality soil that keeps the roots healthy and vigorous. Line the base of  pots with terracotta fragments, partly to reduce the size of pot holes but also to encourage moisture retention.  Division of larger plants is required in order to keep them to a manageable (liftable) size.  Division must be done gently and with care, leaving a minimum of 3 corms and sterilising the wounds made by carefully wiggling corms apart.  Note the direction of corm development, and place the newly separated divisions to give maximum room for future development.
In 2016 Jojn Simmons organised a group purchase of 30 plants for NDOFS members.  These plants were cloned from a wild individual in the Buderim area.  Hopefully all these plants were repotted as recommended last year (2016).  "My plant took a beating from ex-TC Debbie, and is now happy again but not flowering this Spring.  I understand that some of the 2016 generation are flowering, which is good news and a sign of good culture." says John.
By John Simmons