The popularity and quality of expert-led plant and flower tours means it's never been a more exciting time for those with a keen interest in botany. Dedicated flower tours take participants to a diverse range of destinations to encounter and study exotic species in their natural habitat. |
While even for the absolute beginner it can be exciting and fulfilling, learning as much as possible beforehand can greatly enhance the experience for those heading out on flower tours. Understanding some of our flowering plants' unusual behaviours provides an excellent insight in many species.
The World of Flowering Plants
While not a term usually associated with the plant world, scientists and botanists have discovered that some flowering plants do, in fact, exhibit certain behaviours. The difference between "normal" behaviour (as displayed by humans and animals) and how plants behave in response to their environment is that it very often happens a lot slower, so we may not even notice it.
Basic Growth Behaviour
At the most basic level, growth is, in itself, a behaviour, but some plants adapt their growth to environmental conditions and have the ability to change if conditions change. For example when they need sunlight, some grow or bend towards the direction of the sun (phototropism), and if they need water the roots will grow down deeper into the soil (the ability to tell the difference between up and down direction is called gravitropism). Climbing flowering vines actually grow out in search of something on which to attach – this is called twining.
More Unusual Behaviour
Closing at night: Quite a few species close their petals at night and unfurl again in the morning. This highly evolved process is called nyctinasty and occurs in crocuses, tulips, poppies and hibiscus, among others. How it happens is not a mystery – when the air cools in the absence of sunlight the bottom petals grow faster than the top ones, causing them to shut – but why some do it and others don't is not so clear. One theory is that it’s for protection from cold, another is that it helps to conserve energy, and another is that it keeps pollen dry and therefore easier to transport by insects. The most intriguing (if true) theory is that it is a defence mechanism – suggesting that it allows nocturnal predators a clearer view of herbivorous ground prey that may otherwise have eaten the blooms.
Fast food pollen producers: Researchers have discovered a fascinating ability of flowering nettle plants that encourages cross-pollination to ensure greater evolutionary adaptability. We know that when a bee lands on a flower and finds no nectar it will fly to a new plant entirely, rather than simply move to a new bloom on the same one. But the flowering nettle has developed a mechanism where as soon as nectar is collected, the pressure of the bees' weight causes the stamen to tilt towards the centre of the flower – giving it an instant refill of pollen. When the next bee lands looking for nectar, even though the flower is now empty the bee will still collect pollen on its feet before it flies away in search of a new plant. This ensures cross-pollination.
Sexual deception of orchids: Orchids are masters of deception when it comes to attracting potential pollinators. In some species, the sexual organs (anther and pistil) look exactly like the insects they're trying to attract, so when the insect lands expecting a mate the pollen is collected and transported to other plants of the same species. Others emit pheromones that mimic the insect's own scent, drawing them in and setting them up to collect and transmit pollen on their feet. In many cases, an orchid species can only be pollinated by a specific species of wasp in this way.
Botany is an endless source of inspiration and fascination – and it seems that the more we learn about our amazing plant life, the more questions we have…
Marissa Ellis-Snow is a freelance nature writer with a special interest in wildflowers. As a passionate lover of botany, Marissa chooses the expert-led flower tours organised by Naturetrek, which have brought her unforgettable encounter with a wide range of plant species in some of the most spectacular regions on Earth.
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