Image Credit: Anne Hayes

GALLERY: The orchids of Australia

  • BY Dr Noushka Reiter |
  • July 18, 2017

Australia's 1700 orchids are the jewels of our flowering plants.

WITH MORE THAN 100 genera of orchids in Australia – the majority of which are ground-living and found nowhere else – it is impossible to cover the diversity without the weight of a large book.

We have more than 1700 of the 25–30,000 species in the Orchidaceae family known globally, yet, regrettably, 25 per cent of orchid extinctions occur here. In part our species are vulnerable because they require symbiotic relationships with specific types of ‘mycorrhizal’ fungi to grow and germinate, and many are pollinated by a unique species of pollinator.

 

Australian orchids

Eastern underground orchid (Rhizanthella slateri): Confined to small patches in eastern Australia, bizarrely, this cryptic, endangered species completely lacks chlorophyll, relying on its fungal partner for nourishment. The seed of this genus is unusual among Australian orchids, as it is carried in a berry-like fruit, in contrast to the dust-like seed of others. The flowers are thought to be pollinated by fungal gnats and the seed is eaten and distributed by bandicoots. (Image Credit: Anne Hayes)

 

Australian orchids

Veined helmet orchid (Corybas diemenicus): Resembling a snail, this tiny orchid has an intriguing pollination system. To hand-pollinate it, you need to remove the entire top part of the plant (the boss), in order to expose the reproductive parts (pollinia and stigma). This winter-flowering species is common in moist habitats throughout Victoria and NSW. (Image Credit: Anne Hayes)

Australian orchids

Orford leek orchid (Prasophyllum Viretrum): This endangered species is known only from a few small populations near Orford, Victoria, and on heavier alluvial clays on the Victorian plain. This species was only described in 2006. It's thought to require Ceratobasidium fungi for germination, but its degree of dependence on the fungi throughout its life cycle isn't known. This species provides a nectar incentive and attracts various pollinators. (Image Credit: Anne Hayes)

Australian orchids

Wax-lip orchid (Glossodia major): This bright-purple orchid is common and widespread, forming fields or colour in all states except WA and the NT. Notoriously difficult to propagate, it is germinated by Sebacina-like fungi and thought to be pollinated by bees. (Image Credit: Anne Hayes)

Australian orchids

Metallic sun orchid (Thelymitra epipactoides): One of our most majestic orchids, this species was once widespread in southern Australia. It is known from about 1000 plants in Victoria and SA. Conservation efforts in Victoria have led to the reintroduction of up to 3000 plants within its former range. This plant mimics nectar-producing plants to attract bee pollinators. Research suggests that Tulasnella-like fungi are required for germination. (Image Credit: Anne Hayes)

Australian orchids

Sand-hill spider orchid (Caladenia arenaria): First described in 1882 from sand-hill habitats among native pines in NSW, this species is endangered, with only a few thousand plants remaining in the wild in NSW and Victoria. It deceives a thynnine wasp into pollinating it. Its seed only germinates symbiotically in the presence of a fungal partner, Sebacina vermifera. (Image Credit: Anne Hayes)

Australian orchids

Eastern mantis orchid (Caladenia tentaculata): Found throughout Australia except the NT and Tasmania, this large spider orchid is pollinated by a thynnine wasp. It is unusual in that it occurs in a wide variety of habitats and varies in size throughout its range. Its thought that its ability to use several different types of Sebacina fungal partners, and the widespread distribution of its wasp pollinator, gives it a competitive advantage over endangered orchid relatives. (Image Credit: Anne Hayes)

Australian orchids

Emerald lip greenhood (Pterostylis smaragdyna): This winter-flowering orchid is germinated with fungi in the genus Vertobasidium. It's known from Victoria, SA and NSW. This species is thought to be pollinated by Mycetophilidae flies, but whether that's for nectar reward or due to some type of deceptive mimicry is unknown. (Image Credit: Anne Hayes)

Australian orchids

Elfin leek orchid (Prasophyllum sp.): This is actually a complex of several species lumped in as one, and the odour they produce is something like lemon sherbet. The species pictured is endangered and confined to long-leaf heathy box country in western Victoria. It's thought to be germinated by fungi in the ceratobasidium group. These species attract numerous pollinators with sweet smell. (Image Credit: Anne Hayes)

Australian orchids

Common bird orchid (Chiloglottis valida): Widespread and diminutive, this species resembles a bird with its mouth open, and is found throughout Victoria, SA, TAS and NSW. It is pollinated by male wasps, which are attracted to the flowers from some distance away by pheromones. It's thought that it has two geographically distinct thynnine wasp pollinators, attracted by two distinct odours in different parts of the range. (Image Credit: Anne Hayes)

Australian orchids

Audas' spider orchid (Caladenia audasii): The Audas' spider orchid is one of Australia's most endangered plants, with just five remaining in the wild. It is currently listed as nationally enangered and is known to grow only in two ironbark forests sites in Victoria. (Image Credit: Anne Hayes)

Australian orchids

Grampians duck orchid (Paracaleana disjuncta): The small, oval leaves of this species emerge in May, withering by the time a single stem is produced. It bears a flower from November to January with a remarkable resemblance to a duck in fight. This orchid is pollinated by wasps that are tricked into thinking the flowers are females of their own species. It is threatened in Victoria but common in WA, and is reliant upon a baby-pink coloured species of Tulasnella fungus to grow. (Image Credit: Anne Hayes)

Australian orchids

Queen Sheba (Thelymitra speciosa): This flamboyant beauty is confined to WA and is not considered threatened. It grows in open, sandy clays in exposed plains within the wheatbelt. It's reliant upon Tulasnella fungi for germination. Orchids of this genus often mimic other nectar-providing plants in order to be pollinated, typically by bees. (Image Credit: Anne Hayes)

Australian orchids

Blunt greehood (Pterostylis curta): This diminutive greenhood is widespread in all states except WA and the NT. It flowers from winter through to summer and forms spectacular colonies of hundreds of plants. it is germinated by Certobasidium fungi and pollinated by Mycomya fungus gnats. (Image Credit: Anne Hayes)

Australian orchids

Leafless tongue orchid (Cryptostylis hunteriana): This species lacks leaves and draws all it nutrients from the decaying leaf matter around it through its fungal partner. This vulnurable orchid with velvet-like flowers is confined to parts of Victoria, NSW and QLD, and pollinated by an ichneumon wasp, Lissopimpla excelsa. (Image Credit: Anne Hayes)

Australian orchids

Purple beard orchid (Calochilus robertsonii): As the name suggests, the labellum (large, lip-like petal) of this species resembles the scraggly beard of a fairy-tale wizard. The species is widespread, and found throughout New Zealand and all Australian states, except the NT. (Image Credit: Anne Hayes)

Australian orchids

Wimmera spider orchid (Caladenia lowanensis): This striking, vulnurable orchid is known from a few thousand plants growing in open bulloke woodlands in Victoria's northern Wimmera. Research has shown that the Wimmera orchid shares its thynnine wasp pollinator with at least eight other orchid species. (Image Credit: Anne Hayes)

Australian orchids

Bell flower hyacinth orchid (Dipodium campanulatum): Known from fewer than 50 plants in Victoria, and a few hundred in SA, this species is in the process of being listed as nationally endangered. These plants lack chlorophyll or leaves, sending up a large flower spike during summer, which, after pollination (potentially by bees), produces many pods of tiny seeds. It's thought that these orchids are completely reliant on their Russulaceae fungal partner, which also colonises the roots of eucalypts. (Image Credit: Anne Hayes)

Australian orchids

Sunshine diuris (Diuris fragrantissima): This stunning purple orchid once widespread throughout the basalt grasslands of the Melbourne area, but now persists in the wild in only one original population encircled by houses, railway lines and factories. Conservation has been intensive and has led to reintroductions in other grasslands around Melbourne. It is thought to be pollinated by bees that are attracted to the lillies growing in the grasslands, and is germinated by Tlasnella fungi. (Image Credit: Anne Hayes)

Australian orchids

Stuart Mill spider orchid (Caladenia cretacea): This endangered orchid is restricted to box iron-bark forests in northern and western Victoria near Stuart Mill and is known from fewer than 1000 plants in eight populations. This orchid is thought to use food mimicry to attract native bee pollinators. Conservation efforts currently include propagation and habitat protection. (Image Credit: Anne Hayes)

Australian orchids

Desert greenhood (Pterostylis xerophila): Known from only a few hundred plants on rock outcrops in the deserts of Victoria and SA, the desert greenhood is thought to be pollinated by fungus gnats and germinated by Ceratobasidium fungi. These solitary plants have leaves at the base of their stems, which are completely withered by the time of flowering in spring. (Image Credit: Anne Hayes)

Australian orchids

Crimson spider orchid (Caladenia clavescens): Only discovered in 2007, this endangered orchid is known from very few plants in Victoria's central Goldfields. Conservation efforts led to the reintroduction of 60 propogated specimens into the wild in 2012. This orchid is thought to deceive wasps into pollinating it and is reliant upon Sebacina-like fungi to germinate. (Image Credit: Anne Hayes)