Sundew Trapping SpeedsAlthough most sundews eventually fold over prey, some Drosera species curl around prey much faster than others. Part of this depends on the type of food it is catching. If an insect is trapped and is struggling a lot, this will greatly speed up the time at which other tentacles will curl around the prey. This can also be due to whether or not the sundew has "snap tentacles".
Snap tentacles are specialized structures in that they do not contain dew. They are typically at the very edge of the leaf. When "teased", these tentacles quickly fold inward. These are very noticeable on D. burmannii, which can close over prey in merely seconds.
Observe the elongated, red snap tentacles on the above left picture of D. burmannii. They are "circling" the outside of the plant. Snap tentacles are also visible on the above right picure of D. admirabilis. Look to the bottom-right corner.
The fastest- trapping sundew is D. glanduligera. The tentacles have as fast a reaction time as a Venus Fly Trap. Pygmy sundews are also very fast, and can trap insects in only a few minutes. Most South African and South American sundews take up to a few hours before you can see visible leaf movement. Drosera capensis and others such as D. regia, D. rotundifolia, and D. admirabilis curl up their leaves around prey.
D. scorpioides has long tentacles Drosera burmannii traps bugs quickly
that are great for trapping insects
Two examples of sundews that exhibit mostly tentacle movement, and little or no leaf movement inlude: D. binata, and D. schizandra. However, if fed small enough bits of food, almost all sundews will only exhibit tentacle movement, and the leaf will not fold over it.
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