Orchids go to great lengths to attract the insects that are vital to their survival.
Like humans, they put on a pretty dress, slap on some lipstick and perfume, flirt and promise sexual favours and gifts (but do not always deliver). Some even resort to trickery and traps via a sort of passive aggressive courtship that leaves their suitors frustrated but unharmed.
Devious or inspired?
Imagine you are one of the 25,000 or so wild orchid species trying to make sure that pollination takes place while your flowers are in bloom. You need the insect to find and choose you over the multitude of competitors in the area.*
Can we blame them for indulging in a bit of sexual deception and manipulation?
Don’t be fooled by appearances
Some members of the orchid family mimic plants, such as lilies (e.g. Phaius tankarvilleae), that typically trade pollen or nectar but may not actually provide any such satisfaction to the visitor – or trick pollinators with ‘pseudo’ pollen and nectar, a form of counterfeit payment for services rendered.
One orchid (Bulbophyllum nocturnum) may even have adapted some of its features to resemble slime mould, the favourite food source of the midge.
Like many other flowering plants, orchids are not above using the age-old ploy of bright colours to attract butterflies and birds that are active during the day (or white to attract nocturnal insects in the dark).
Do you smell a rat?
In a similar way, many orchids also use scent to attract pollinators. Some attract flies with putrid smells resembling dung or rotting flesh or moths with sweet and musky fragrances (including the vanilla and cinnamon fragrances that also attract people).
But a few shameless Orchis temptresses (mostly in Australia) go further and lure amorous male bees and wasps by exuding a scent that mimics the pheromones released by receptive female insects.
If it looks & smells like a duck, then is it a duck?
A surprising number of orchids disguise their flowers as female insects in order to attract pollinators under false pretences. Examples include bees (e.g. Ophrys Apifera), wasps (e.g. Drakaea_glyptodon – top Hammer Orchid pic), flies (e.g. Ophrys insectifera) and butterflies (e.g. Psychopsis papilio).
One orchid even imitates a female fly flashing its genitalia to passersby in a blatantly erotic but misleading manner.
In addition to misleading flower shapes and colours (including ultraviolet reflection), orchids that mimic insects also provide tactile stimuli that excite and maintain the interest of their ‘suitors as it tries unsuccessfully to copulate with the cunning but frigid imposter.
After a while, the frustrated bees and wasps fly off in search of more authentic female companionship – taking the flowers’ pollen sacs with them.
Another trick is to simulate an enemy insect, which the male bee tries to drive away from his territory. As the bee strikes at the flower, tiny yellows sacs of pollen are attached to the head of the bee.
(Check out these great youtube videos to better understand the ingenuity of these incredible plants and how they deceive and manipulate their suitors – various bee & wasp mimics (here – excerpt by David Attenborough) and hammer and bucket orchids (here – excerpt by Richard Dawkins)).**
(Some orchid flowers look like larger animals, such as flying ducks (Caleana Major), white egrets (Habenaria Radiata), and monkeys (e.g. Dracula Simia), but clearly these plants are not trying to attract these species! Check out more amazing monkey faces – here.)
Playing hard to get (or working smart)
So why do orchids go to all of this trouble? Why not simply produce large amounts of easily accessible nectar and pollen?
Firstly, this takes lots of energy. It can also attract unwanted species that eat the whole flower or can tap the nectar without performing the necessary pollination function.
Secondly, there is a good chance that pollinators will get lazy and be less tempted to venture far and wide in search of different colonies of orchids. This can lead to in-breeding that is likely to eventually result in decreased biological fitness of the population. (Would an orchid with two heads simply mean more flowers?).
A single, highly devoted pollinator helps to differentiate from the masses and ensure suitors will seek them out even when there is lots of competition or they are spread out over large areas.
(There is a classic ‘orchid porn’ story involving Charles Darwin and very deep throated flowers on Madagascar (Angraecum sesquipedale) whose nectar can only be tapped by moths with an extra long proboscis.)
Such strategies can also help to maintain genetic integrity by making mutants less attractive or available to pollinators. Each flower needs to be just different enough that the insect doesn’t think they are repeating their mistake but not too different.
Survival of the unpollinated
A number of enterprising orchids have hedged their bets and learnt to self-pollinate in case their best laid plans come to nought, especially in colder regions where pollinators are particularly rare, or can produce offshoots or plantlets along their stems to overcome celibacy.
Other orchids have resorted to force and treachery to increase the odds of successful pollination.
Sirens such as Bucket Orchids (featured in the Richard Dawkins video) lure unsuspecting pollinators into their lair – only to plunge the insects into watery bulbs or deep columns from which there is only one exit. The flowers then deposit pollen sacs on their visitors as they climb out past the anthers.
Devious green hoods, for example, have a hinged lip that swings backwards when touched by an insect, knocking them into the long tube.
Other species have a flower structure that can catch and hold fungal gnats.
(All orchids – whether they grow as epiphytes on top of other plants, such as on tree bark high up in rainforest canopies, on a rocks and cliff crevices, or in the ground in grasslands and forest floors – are dependent on mycorrhizal fungi for germination and seedling growth and in some cases throughout their life to provide energy and nutrients.)
Not all orchids set out to deceive
Around two thirds of orchids do provide nectar and pollen to their suitors.
And some orchids are pollinated by male bees that visit the flowers to gather the fragrance they require to blend with other volatile chemicals from certain leaves and fungi to produce their own pheromones (e.g. one species of euglossine bee collects the fragrance of Stanhopea orchids).
As Michael Pollan explains, deception is not a perfect solution but it works well enough to keep these plants going:
“Orchid deception can succeed only in a world where most things in nature really are what they seem: where the smell of rotting meat signals rotting meat, where flowers really do offer nectar and don’t dress up as bugs… For while sexual deception doesn’t fool all of the pollinators all of the time, it does fool some of them some of the time, and for an orchid that is quite enough.”
A good flower can be hard to find
Despite being the second-biggest, flowering-plant family in the world (after Asteracae), these flowers are frequently difficult to find – especially the ones that live out their entire lives as recluses below the soil surface (relying on ants and other subterranean pollinators) or that only flower at night to attract nocturnal insects.***
[Ed 16/9/2014: I’ve just been informed by someone in the Orchid Society of Canberra that the Orchidacae family may be ahead of Asteracae in terms of taxa – so probably should have written something like ‘Despite being one of the biggest flowering plant families in the world…’ instead. Whoever said that size didn’t matter?]
It is quite common for terrestrial orchids (which account for most of the orchids in Australia) to remain dormant, in the form of an underground tuber, for up to six months of the year – with no visible vegetation above the surface.
When underground tubers re-sprout, leaves are usually present for many months before flowering but they may be difficult to distinguish from other vegetation or hidden by leaf and bark litter.
Flowering is triggered by seasonal rain or other factors but these plants may wait up to three years for favourable environmental conditions before they emerge (e.g. in the case of prolonged drought). Not all orchids flower every year and even when they do, many of the blooms are only a few millimetres in size and may only last a few days.
Unfortunately, many orchids are hard to find for another reason – as they are rare or endangered.
Although these plants grow in many different climates and environmental conditions from humid jungles to sandy deserts and alpine cliffs, they may only be present in tiny numbers or exist in very remote places.
For example, the critically endangered Canberra spider orchid (Arachnorchis actensis) is found only in the ACT, and in only three places (small areas of Mount Majura, Mount Ainslie and the Majura Valley). The number of plants in each colony may reach as low as ten. (More than 70 per cent of Australian orchids are not found anywhere else in the world.)
Many threatened orchid species occupy specific habitats that are being damaged by human activities or at risk due to development or natural hazards (the effects of which may be amplified by climate change). Even overshadowing may be a problem as trees and shrubs grow up around isolated colonies.
Individual plants and colonies may also be eaten by grazing animals and birds or trampled by stock. Other hazards include weed infestation and disease.
But at least the news is not all bad. (Check out this inspiring story about some rare and endangered orchids bouncing back after the 2009 Black Saturday fires in Victoria – here).
Loving plants to death
Unfortunately, avid orchid fans are also sometimes responsible for destroying the fragile plants that they love so dearly. This is one of the reasons that the exact location of some sightings is often not published.
(Check out this great video about efforts to protect the Caladenia spider orchid, one of the rarest plants in the world, from collectors, photographers and other threats – here.)
Orchid collecting began after 1818 when a box of tropical plants was sent from Rio de Janeiro to London using orchids as packing material and one of the plants bloomed on arrival. (This event is a testament to the fact that most orchids are very unattractive when not in flower.)
This sparked a serious bout of ‘orchidelirium’ during the Victorian era – with expeditions of orchid hunters overcoming dangerous animals, tropical diseases, hostile tribes and other hazards in their quest to find specimens to display in the glasshouses of the wealthy. (Many of the original orchid houses in stately homes are now being restored to their former glory.)
Nowadays, most orchids are protected and must not be collected in the wild without permission. Overseas orchid collecting trips, where plants are transported across international borders, might even require a phytosanitary certificate from the collector’s home country, a collection permit from the plant’s native country, and a CITES permit to transport it between the two.
Although the average punter is likely to overlook the plainer and insignificant blooming varieties in favour magnificent blooms, genuine collectors lust after even the least flamboyant of orchids – the rarer the better.
(A famous prosecution in the USA involved the poaching of rare orchids in south Florida in 1994. The perpetrator, Laroche, maintains that he was taking the Ghost Orchid and other protected plants from the wild in order to cultivate them in a plant laboratory and undermine the black market in orchids by flooding the market with large numbers of these otherwise rare and endangered species.)****
As such, these plants continue to fascinate – and to torment – collectors as their orchiastic urge can never be fully satisfied. As Orlean explains:
“…even if you manage to find them and then possess them, there is no guarantee they won’t die or change…To desire orchids is to have a desire that can never be fully requited. A collector who wants one of every orchid species will die before even coming close.”
Silk imitations (e.g. here) are also beautiful and can avoid much of the hard work and inevitable heartache involved with real orchids – but are no match for the real thing.
Amazingly, we are still finding new species as shown in this 1993 video about collecting Dracula species in Ecuador – even as the rainforests that house them are being destroyed (here).
But you don’t have to go that far to find magnificent orchids. This short video shows an impressive selection that are found in Western Australia (here) and this page contains links to great amateur videos by ‘Orchid Hunter Australia’ in a small nature reserve on the outskirts of Melbourne, Victoria (here).
A labour of love
Orchids may be high maintenance, temperamental, and demand patience – but gardeners, plant breeders and cooks will tell you that they are well worth the effort.
For example, the vanilla orchid (Vanilla planifolia) is a climbing plant that produces the edible seed pods that are dried to form highly prized vanilla beans. However, these plants do not produce vanilla beans for the first three years.
When the flowers finally appear, they only stay open for one day and must be pollinated within 12 hours of blooming. Under cultivation, each flower on each orchid must be hand-pollinated using a pencil, small paintbrush, or other similar device to take pollinium from the anther of one flower and transfer it to the stigma of another.
This is a painstaking process as each flower opens at a different time of the day over a period of several weeks. It takes nine full months for the seed pods to mature enough to harvest and every pod matures at a different rate. Following the harvest, the seed pod curing process takes another three months.
(Check out this short video about Fair trade vanilla in Uganda to see how hand pollination is done – here).
It’s easy to see why orchids have inspired such passion and interest over the years – and a tragedy that so many of these incredible plants are threatened with extinction.
(For more on orchids – see my post about the Canberra Spring Orchid Show ‘Day of the Orchids’ – here.)
* Although hybrids do occur naturally, they are generally sterile.There are also over 100,000 registered hybrids produced by orchid breeders.
**Another good clip is Wild Orchids of Israel:Seduction of the Long-horned Bee 8mm to DVD by CinePost – YouTube (here) There are lots of videos of different types of orchids in cultivation at OrchidWebTV – YouTube (here)
**** This case was discussed in a New Yorker article ‘Orchid Fever’ by Susan Orlean (1995) and was later the subject of a book by Orlean called ‘The Orchid Thief’ (1998) and a film called ‘Adaptation’ (2002). Check out this clip from the film to see hauntingly beautiful white-flowered Ghost Orchid (here).
Strange fact: The word orchid is derived from the Greek word (orchis) for testicle because of the shape of the twin root tubers in some species of the genus Orchis.
Sources: (Sites accessed 12-13 Sept 2014)
- ‘Orchid‘ by Calaway H. Dodson at Encyclopaedia Brittanica online.
- ‘Love and Lies‘ by Michael Pollan at National Geographic online (Published Sept 2009)
- ‘World’s first night-flowering orchid discovered‘ by Tom Lawrie at Australian Geographic online (Published 23 Nov 2011)
- ‘Orchids found to be sexual deceivers’ by Anna Salleh at ABC Science Online (Published 26 June 2000)
- Wikipedia – Orchidacae; Caleana major; The Orchid Thief
- Orchid Care Tips website – Fragrant Orchids & Identifying Orchids
- Survey guidelines for Australia’s threatened orchids. Guidelines for detecting orchids listed as ‘Threatened’ under the Environment Protection & Biodiversity Conservation Act 1999. (Commonwealth of Australia 2013)
- ‘The Canberra spider orchid – an endangered species‘ ACT Government Environment & Sustainable Development fact Sheet (Nov 2012)
- ‘Australian Native Terrestrial Orchids‘ fact sheet produced by the Bribie Island Orchid Society
- ‘History Inspired | Orchidelirium‘ by Sarah Janks at Sarah Janks Blog (Posted 13 May 2014)
- ‘Orchid Fever’ by Susan Orlean in The New Yorker (Published 23 Jan 1995)
- ‘The Vanilla Bean Orchid‘ by Chris McLaughlin at Vegetable Gardener (Posted 27 Nov 2012)
- King-in-his-carriage (hammer orchid)/Drakaea_glyptodon.jpg By Brundrm (Own work) on 14 October 2010. Shared under a CC3.0 licence via Wikimedia Commons. Uploaded 20 November 2012.
- Phaius tankarvilleae (flowers) at Lanai, Munro Trail [Greater Swamp-orchid, Swamp Lily] By Forest & Kim Starr on 5 April 2007. Shared under a CC-BY-3.0 via Wikimedia Commons. (Uploaded by BotMultichillT on 9 March 2009)
- Ophrys apifera [Bee Orchid] By Ramin Nakisa on 20 July 2002 (original upload date). Shared under GFDL or CC-BY-SA-3.0 from Wikimedia Commons
- Psychopsis papilio [Butterfly Orchid] By Brocken Inaglory (Own work) in 2007. Shared under GFDL or CC-BY-SA-3.0-2.5-2.0-1.0 via Wikimedia Commons
- Ophrys insectifera, Ausserfern, Austria [Fly Orchid] By Bernd Haynold (Own work) on 10 June 2004 and shared under GFDL or CC-BY-SA-3.0 via Wikimedia Commons (Uploaded 25 December 2004)
- Caleana major, off Elvina Track – Ku-ring-gai Chase National Park, Australia [Flying Duck Orchid] By Poyt448 Peter Woodard on 8 October 2010 (Own work). Shared under a CC0 licence via Wikimedia Commons
- Flower of Habenaria radiata in wetland of Japan [White Egret Orchid] taken by Alpsdake (Own work) on 27 July 2013. Shared under a CC-BY-SA-3.0 licence via Wikimedia Commons. Uploaded by Rotatebot on 16 Aug 2013
- Monkey face orchid. By Dave Bezaire & Susi Havens-Bezaire (www.ColumbusGVTeam.com) on a Habitat for Humanity Global Village mission trip to Guayaquil, Ecuador on 27 June 2008. Shared under a CC BY-NC-SA 2.0 licence via Flickr
- Xanthopan morgani. Natural History Museum of London [Darwin’s moth] By Esculapio (Own work). Shared under GFDL or CC-BY-SA-3.0 via Wikimedia Commons
- Pterostylis coccinea [Greenhood] By BerndH on 27 September 2003. Shared under GFDL or CC-BY-SA-3.0 via Wikimedia Commons (Uploaded 4 Feb 2005)
- Canberra Spider Orchid Arachnorchis actensis By Waltraud Pix. Published at Friends of Mount Majura website on 22 June 2008. Shared under a CC-BY-NC-SA-4.0 licence.
- Orchids in Golden Gate Park Conservatory [San Francisco] By Mannat Kaur (Own work) on 14 March 2012. Shared via a CC BY-SA 3.0 licence via Wikimedia Commons. (Uploaded by Drminnie on 10 Sept 2012)
- Ghost Orchid2 [Dendrophylax lindenii] By Mick Fournier / HBI Producers of Fine Orchids (Own work) in July 2007. Shared under a CC-BY-2.5 licence via Wikimedia Commons. Uploaded by Random Replicator on 18 July 2007
- Vanilla planifolia in Goa, India By J.M.Garg (Own work). Shared under a GFDL or CC-BY-3.0 licence ia Wikimedia Commons