Botanists - a vine question.

[silenus]

I just potted a couple of mandevillas a few days ago, and they are already winding themselves around the trellis. A question floated through my mind: how do vines know to, well, wind? What mechanism makes them coil? Do they just rotate until they touch something then cling? Is it electric in nature, or does it involve pressure on the cells on one side of the vine or another?

Nothing earthshaking, just curious.

[carnivorousplant]

Dammit, I thought there was another orchid person on the SDMB.

[Squink]

Thigmotropism is what you seek.

Bonus Botany word: Guttation.
This word can be handy when you overwater your philodendron, and someone asks you about the drops of water at the edges of the leaves.

[silenus]

Thank you. Just what I needed to know.