Drosera burmanii (Tropical Sundew) Northern Territory, Australia When I worked in a plant nursery, there was one corner of the yard that got more attention from almost all the children, as well as many of the not-so-children - the carnivorous plant section. And really, it's hard not to be fascinated by these unusual sneaky predators, plants that can seem to reach out, grab a passing insect, and eat it. All plants move in the sense that they bow with the wind, or twine up a fence post, and some even move across the ground (some trees can "walk" up to 20m in a lifetime!), but generally these things happen muuuuch sloooower than what we can see.
So, if speed is your thing, then the rock-stars of the carnivorous plant world are Venus fly traps, which can snap shut quickly enough to snag their prey before they fly away, but if you are after something slightly less flashy, but no less fascinating, then sundews (Drosera) might be more your speed. These carnivorous plants are a little more relaxed. They casually lure their prey to land on their leaves by covering them with droplets on the end of long hairs, luring thirsty insects to them with the promise of a refreshing drink (hence "sundew" and the Latin "Drosera" from drosos = dew drops). Instead they find the droplets are a sticky gluey trap and the more they struggle, the more they become stuck. As soon as the insect is stuck, the plant then leisurely starts to fold the leaf together, adding more sticky droplets, and covering the insect. Even worse for the victim, the droplets aren't just sticky, they are a made up of a soup of enzymes (like the digestive liquid in your stomach) that slowly set about digesting the animal from the outside in. The yummy insect juice is then absorbed by the plant and the leaf reopens. So you might wonder what the point of this is, other than to provide nightmare fuel to small baby bugs cuddling with their parents at night. Why go to this trouble when other plants don't? The reason is that sundews grow in places where many other plants can't: sandy dunes, bogs, swamps, places where nutrients are harder to come by. By snatching passing insects they can supplement their diet (especially Nitrogen) letting them thrive and grow in tough places. With this advantage they have found homes on every continent except Antarctica (although somehow there are only three species in all of Europe). The picture at the top of the page is Drosera burmannii which I found growing in a sandy creek-side, south of Darwin in Australia's Northern Territory. It has one of the fastest closing leaves for a sundew- you can actually watch the leaf curl around a newly caught insect! This species also has a rather unusual distribution for plants in the region, being found from sub-tropical India, through Southeast Asia, Japan and northern Australia. With very small seeds, sundews may be able to travel further than many other plants, allowing it to spread out across these large areas. Another interesting thought is how do these plants manage to get insects to pollinate them without just eating them? The flower stalks for almost all species are very long, sticking way up above the leaves, so it seems that the plant hopes that insects visiting the flowers will not get distracted by the yummy looking dew, and do the job of pollination without getting liquefied. This is a risk as the plants definitely trap the same insects that pollinate them, but so far, they seem to be doing ok at getting the best of the insects both ways!
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