Hope you are all as happy as I am that today is finally Friday. Not sure what your plans are, whether it be going out on a night or perhaps going to watch the awesome new Deadpool movie (watched it yesterday it is awesome!!) whatever it is... right here and right now we are going to learn about my chosen Family Of The Week which just so happen to have a whole exhibition at Kew Gardens (where all the pictures below are from!)
Orchidaceae:
Number of species: 27,000+ - this number remains fairly dynamic as new species are added every year.Geographic range: Cosmopolitan distribution (Occurs in almost every habitat apart from glaciers).
Conservation status: remains variable amongst different species, but ranges from least concern to endangered.
This family of flowering plants are the masters of deceiving their pollinators to carry out their bidding with no reward for the poor, confused pollinator. How do they manage such sly tactics? That is what we are going to explore for this families characteristics.
Characteristics: Deceptive pollination tactics
Some where during this families evolution several orchid species ended up realising that instead of placing valuable resources into nectar production, they could on a far more misleading approach. Today a third of all orchid species have perfected their visual, aromatic and tactile deceit, all in the name of pollination.
Orchids carry out deception in many ways, one of which is sexual deception that leads to the act of pseudocopulation. Pseudocopulation translates into false copulation, or, false sex. These orchids provide no reward for their unfortunate pollinator, instead the orchid mimics the body of and even the sexual pheromones of the pollinators female counterpart! Cheeky!
Sexually deceptive orchids often mimic the females of the hymenopteran family (wasps, bees and ants). They lure a male hymenoptera to land and copulate with the flower, well pseudocopulate, during this time the orchid uses a sticky glue to stick its pollinia (sack of pollen) on to the back of the male insect. And BAM! The orchid has successfully pollinated itself at the expense of a now very frustrated pollinator.
Other than sexual exploitation, other orchids have decided to go down a path a little less promiscuous. Dendrobium sinense is pollinated by the hornet Vespa bicolor, this orchid uses its floral aroma to attract the hornet for pollination to occur. However, this is no normal floral aroma, this orchid produces (Z) - 11 - eicosen-1-ol, a compound that is found in the alarm pheromones of the Asian and European honey bee. Why would hornets be attracted to this chemical? Well, believe it or not but hornets actually harvest honeybees to feed their larvae, I know, weird. Basically this orchid triggers the predatory instinct within the hornet, so this hornet arrives at the plant (the source of the alarm pheromone) lands on the orchid and is planted with the orchids pollinia.
Ultimately these beautifully complex orchids owe their successes to their pollination tactics that can only be achieved through their remarkable labellum morphology. The labellum is the one that is shaped in a myriad of ways in order to decide the pollinators sight. These pollinators are not complete fools, after realising they have been falsely led on for a sexual encounter they often fly far away from the flower and do not fall for the same flower twice. This may sound like a disadvantage at first, but actually there is hidden genius behind it. The pollinator is so utterly repulsed at being sexually exploited, or cheated out of a meal as in the case of the hornet that they will carry the pollen of that orchid far, far away thereby eliminating any possibility of self pollination or inbreeding.
Yes, they are crafty plants. But look through their deceiving ways and you can only regard orchids as one of natures most scandalous but most impressive creations.
As I mentioned before Kew has an amazing expedition celebrating the rich diversity of South Americas orchid species. You lucky guys have had a bit of a teaser trailer, because every photo used in this post was taken from the expedition. I had the most amazing mother daughter day out with my mum last week when we visited the exhibit! It's a lot of fun and not something to miss! You have two more days, go, go right now if you can!!
Thats Biobunch,
Over and out.
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