ISTM best as I can tell that vines have a tendency to extend themselves in the direction which allow them to attach to something else. For example, in my backyard I have some vines which tend to grow up a fence and then extend in the air in the direction of nearby tree branches until they make contact with the branch and climb up from there. (This is in more than one place, and the direction of growth is not identical on a compass - it’s determined by a convenient nearby object, again, best as I can tell.)
Assuming this is correct - and I’m not 100% sure it is - is there some process in the vine which directs its growth in the direction of something suitable for attachment? It seems odd, but plants are frequently capable of doing more than one might credit them with at first glance.
A perhaps related question: most vines in my neighborhood (northern hemisphere) wind in a right-hand
helix. Do vines in the southern hemisphere wind in the opposite direction?
In my backyard gardening experience, the vines just grow straight up and wait for the wind to “bend it.” When the wind makes it lean against something - it catches it and grows from there
Most things in biology have some sort of preferred “handedness”. Hemisphere has nothing to do with it; the Coriolis effect is only noticeable for things on very large scales like hurricanes, not on small things like toilets or organisms.
Yes. Some vines show skototropism, that is, they grow towards darkness. In a typical environment, the darkest area around will represent a tree or other thing to climb. This is different from negative phototropism, which means growth away from light. Growing away from the brightest light doesn’t necessarily mean you will grow towards the darkest area.
Once a vine reaches a tree and begins to climb, like most plants it will show positive phototropism, growing upward toward the brightest light.
This is not true in general. The direction that a vine twines depends on its species. Some species habitually twine clockwise, others counterclockwise. If you are seeing most vines twining in one direction, they just coincidentally belong to species that grow that way.
No. The hemisphere has no influence on the direction of twining.
In my attempts to grow asparagus near what turned out to be morning glorys I can tell you the vines are vicious little bastards with far more intelligence than any plant deserves. When I tried to dig them out I discovered that they pre-form themselves underground. The growing tip about 3 or 4 inches long already has leaves formed. They are completely white. Upon some unknown command they whip out of the ground fully formed, turn green and head for the nearest plant.
Are you sure they’re morning glory vines and not bindweed (very similar)? We have bindweed that have taken over almost the entire yard, and are impossible to get rid of.
Yeah, honestly, I don’t know if it’s a factor, but when you look at timelapse footage of seedlings growing, there is often a noticeable circular swaying pattern, which, in the case of twining climbers, seems like it could influence the direction of twining, but that said, There are examples of footage of twining climbers twirling quite conspicuously in either direction (and frustratingly little information about where it was shot, and the period of the twirl)