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South Africa has 28 known species of carnivorous plants, including the world’s tallest. It reaches almost the height of a man, and has hairy leaves, big enough to catch a small bird.
SA also has a species boasting the world’s biggest flower on a flesh-eating plant. (“All the better to lure you with, m’dear”)
FOOD, SEX, CONFLICT AND CARNIVORES
THE HEADLINE above looks like something blazed across a lurid tabloid newspaper. Instead the words are taken from the title of a scientific paper by B Anderson and J J Midgley of the Department of Botany, University of Cape Town.
Their paper, published 5 September 2001, was headed: “Food or sex; pollinator-prey conflict in carnivorous plants” and the botanists were researching the presence of thieves, cheaters, pimps and other naughty criminals trying to upset social relationships in the world’s richest Floral Kingdom
Frank Woodvine had showed me half a dozen species of the flesh-eaters among the fynbos flowers and dancing daises on the mountain top behind Hermanus. Then he lent me some scientific literature on the subject, which I am endeavouring to interpret for TV-soapy watchers. The scientists’ paper says:
“Nectar thieves may leave few rewards for mutualistic pollinators.”
But their experiments show that relationships between plants and partners are sometimes even worse than that.
What is a pretty little flesh-eating flower to do if its thieving, cheating partner grabs all the food and refuses to do its sexual duties?
“The thieves can trigger the extinction of obligate partners”, say the researchers.
Which results in a fate worse than death:- oblivion for generations to come.
But the pretty little flowers are not always the innocent victims they pretend to be.
The bargain which Nature has developed is that the flower ensnares food by luring it into its home, and sharing it with an arranged partner. Then, after a fond embrace the partner is supposed to go off and do the cross-pollination thing. . . but sometimes the flower can’t bear to let him go. She eats him.
[The gender – but not the deeds - of plant and animal can be reversed here. Let’s not argue about sex discrimination in this vital matter.]
Food or Sex. That’s the dilemma. The carnivorous plant has to keep a balance between the two needs, and if it gets too greedy, murder will follow. Which means no more offspring.
It’s tough world out there. Yet it is beautiful, because Nature’s many basic concepts include the idea that close relationships - not only between couples but also between assenting plants and animals in the wild - are vital to the survival of both. This does not mean that life becomes predictable and plain sailing in the botanical world. There are options, and eventualities, and domestic tiffs. These can cause immense strain on sensitive plants and their partners.
There is one cute little spider, for instance, that has become a specialist toy-boy (or toy-girl, I cannot say which) for Mrs (or Mr) Roridula Dentata. The spider lurks around tickling Roridula’s fancy and eating the entrapped food while Roridula’s dutiful (‘obligated’) mate – probably a beetle - is away spreading pollen. It’s the age-old triangular affair, and its no surprise that the researchers have found that in the normally innocent world of flowers, this relationship is, to quote the scientists, “inherently unstable”.
The researchers also found that where ants exist (they seldom survive in many parts of the ultra-protective fynbos kingdom) they could be ideal sex-partners for flowers. Except that they are not interested in sexual or any other obligations other than to their own queen.
“Ants steal a large portion of the prey taken by carnivorous plants,” the researchers report.
Yet again there are exceptions. Nature has many plans. For instance, there are other ants which do reward the carnivorous plant for offering them food. They are careful to come around and remove only the excess prey that the flower has caught – thus avoiding putrefication in the sticky traps. For the flower, its like mating with the rubbish man, but not everyone can have a prince (or princess).
Survival is the big thing in the prolific fynbos. It’s a jungle out there. That’s what I learned while strolling knee-deep among the pretty little wildflowers. |
