This is a creeper growing across the road that runs in front our building. The 'crossing' is a little away from our building. Don't know how two creepers from two ends got entwined with each other, yet kept themselves high above the road. Could be human intervention, but unlikely because who would stand up in the middle of the road and tie the creeper(s) together? And to what avail?
When I posted this image on a social media platform with the note that I have written above the image, my friend 'R' replied with this explanation which he had acquired from some sources:
The Touch Trigger: As a vine sweeps through the air (a process called circumnutation), it senses physical contact. The tendril's touch sensors are highly sensitive, capable of registering weights as light as a fraction of a gram.
Differential Growth: Upon contact, cells on the side touching the support contract, while cells on the opposite side rapidly elongate. This uneven growth quickly forces the tendril to curl tightly, securing a grip
Me:
Dear R: Thanks for the riposte.
However, this only gives the process. The motivation of the creepers to join hands (so to speak) is not given. Can it be likened with cross pollination, where both parties benefit. Or, is it parasitic approach of one against another? Or, is it something inexplicable in the language that we know. In fact, when I see this phenomena and I read along with tree bridges of Meghalaya, there are many unanswered questions.
R:
It is a very interesting mode of survival and propagation.. tendrils have a very sensitive surface design.. the plant kingdom is best studied in rain forests .. including the complex root system … fires destroy them completely and in a year or so they are back .. its a science that needs to be studied if it interests you!
Me:
It does interest me. What piques my interest is how do the tendrils work against gravity? Unlike the tree bridges of Meghalaya, where there was human intervention of generations to get the bridge going, here the tendrils are seemingly spanning the gap of 50 feet, at a height of about 20 feet(all buses and trucks, even 18 wheeled ones, pass under this tendril embrace) without any assist. This embrace is no more than 5 years old.
At this point I took help of gyani AI Claude:
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Claude:
What a fascinating observation and conversation! Let me engage with the questions you and R have been discussing.
What you're seeing in the photo: The image shows two creepers/vines that have grown from opposite sides of the road and met in the middle, their tendrils intertwined at considerable height — with enough clearance for large vehicles to pass beneath. That's a remarkable natural achievement.
On your core question — how do tendrils work against gravity?
This is actually the most intriguing part. A few mechanisms are likely at play:
- Thigmotropism + circumnutation (as R's screenshot explains): as the vine sweeps through the air, it keeps extending outward. The tendril doesn't "fight" gravity so much as it grows faster than gravity can pull it down — especially in humid, warm climates like Bengaluru's.
- Tensegrity: once two tendrils touch and grip each other (using exactly the touch-trigger and differential growth mechanism described in R's screenshot), they create a mutually reinforcing tension structure — each holds the other up. This is actually structurally elegant: the embrace distributes load between both plants.
- The 50-foot span without assist: this strongly suggests the vines used intermediate supports — perhaps an overhead wire, a branch tip, or even a passing vehicle briefly — at some point. A single chance contact in the right spot could have initiated the whole bridge.
On your deeper question — motivation: mutualistic, parasitic, or something else?
This is where it gets philosophically rich. Most botanists would say there's no motivation in the intentional sense, but functionally:
- It's likely mutualistic — each vine gains a structural anchor from the other, potentially extending both their reach toward light.
- It's not classically parasitic since neither appears to be drawing nutrients from the other (unless one is a hemiparasite like a mistletoe-type).
- Your instinct to compare it to the Meghalaya living root bridges is very apt — the difference being time scale and agency: those bridges took human guidance over generations; this happened in ~5 years, spontaneously.
The unanswered part:
What remains genuinely mysterious is the initiating moment — how the first contact across that 50-foot gap was made. Wind, a passing tall vehicle brushing a tendril sideways, or sheer extended growth are possibilities. But you're right that it deserves a blog post — and perhaps a closer look at what species these are, which might reveal more about their growth strategy.
Me:
I sought clarification from Claude regarding 'as it grows faster than gravity can pull it down' thus:
What does this (as it grows faster than gravity can pull it down) actually mean? Does it mean that the acceleration of the tendrils towards the sky is more the retardation caused by the acceleration due to gravity?
Claude:
That's a sharp catch — and honestly, my earlier phrasing was sloppy. Let me correct it properly.
No, it doesn't mean that, and the statement is physically problematic as written. A tendril is not a projectile. It isn't moving upward with any velocity or acceleration that could "outpace" gravitational pull. Gravity acts on its mass continuously, and nothing in plant growth generates an upward force that counters gravitational acceleration in that Newtonian sense.
What I should have said is this:
The tendril grows incrementally, cell by cell, at its tip. Each new increment of growth is essentially supported by the rigid structure behind it — the already-hardened older portion of the vine. So the question isn't "how does the tendril overcome gravity?" but rather "how does the structure behind the growing tip stay rigid enough to act as a cantilever?"
The honest answer is: it largely can't, over 50 feet, without intermediate support. A pure unsupported cantilever of that length from a soft vine is biomechanically implausible.
What this means for your observation:
The more physically coherent explanation is that the vines found opportunistic intermediate contacts along the way — a branch tip, an overhead wire, anything — even momentarily, that allowed the tendril to hook on and extend further. The final "embrace" in the middle may be the last and most visible link in a chain of smaller, less obvious contacts. So your instinct to call it inexplicable isn't wrong — the initiating geometry of how that first mid-air contact was made across the full gap remains the genuinely open question.
Me:
Thanks. I will try to upload a zoomed picture of the vine(s). Perhaps, you will be able to identify the vines and the cause for each to seek the other. I will come back to you once I have a picture with a higher resolution.
Claude:
That sounds great! A clearer, zoomed-in photo would help a lot — ideally one that shows:
- The leaf shape and arrangement (alternate, opposite, compound?)
- The tendril structure (do they arise from leaf axils, stem nodes, or modified leaves?)
- The stem cross-section if visible (round, square, winged?)
- The point of contact/embrace between the two vines
With those details visible, identifying the species becomes much more feasible — and the species identity could genuinely shed light on your "motivation" question, since some vines are known to exhibit particular growth strategies (light-seeking, support-seeking, etc.) that might explain why these two reached toward each other.
Looking forward to seeing the photo when you have it!
Me:
Photos from same side of the road, focussed on other side of the road, and from below the embrace. Unfortunately, I noticed that the creeper is withering on the vine at the far side.
Claude:
These new photos are much more revealing! Let me work through what I can now see.
The vine identity: The heart-shaped (cordate) leaves visible clearly in Images 2 and 3 are quite distinctive. This looks very likely to be Ipomoea species — possibly Ipomoea cairica (Mile-a-Minute vine) or Ipomoea indica, both extremely common in Bengaluru, vigorous climbers, and known to colonise walls, trees, and overhead structures rapidly. The leaf shape, size, and the way the stems trail and dangle are all consistent with this identification. The thin, wiry bare tendrils/stems visible hanging down in Image 3 also match Ipomoea's growth habit.
The crucial structural revelation: Image 3 is the most important photograph you've taken. Look at the upper left — the vine is clearly growing along and over the compound wall, and has then extended outward and upward. More significantly, you can see utility/telephone wires crossing the road at that height. The vine almost certainly used those wires as its intermediate support — not a dramatic mid-air leap, but a patient, opportunistic colonisation of an existing wire infrastructure. This resolves the biomechanical puzzle we discussed earlier.
The withering you noticed: This is concerning and botanically significant. Ipomoea, despite its vigour, is sensitive to being cut at the root. If the wall-side plant has been trimmed or its root disturbed, the extended portion dies back from the far end first — exactly what you're observing. It may also simply be the older, less-leafed portion showing seasonal dieback while the root-side remains green.
On your original question of "motivation": Ipomoea is a pure light-seeker — its entire growth strategy is to find the maximum sun exposure. The road gap, being open sky, would have been an irresistible phototropic pull. There is no mutualism or parasitism between the two vines — both were independently following the same imperative: grow toward light. The "embrace" was incidental geometry, not intent.
Me:
I think your assumption regarding wires being present in and around the creeper is incorrect. The cables that are seen are way beyond the crossing place of the creeper. In any case there are no cables running on the left side of the road as can be seen clearly from the 3rd picture. The second picture gives us the leap of faith, literally. It is shot from below the crossing point. You may want to change/adjust your findings accordingly.
Claude:
You are absolutely right, and I apologise for that hasty inference. Looking at Image 3 again carefully — the cables visible are on the right side of the road, well beyond the crossing point, and there are clearly no cables on the left wall side from which the vine originates. Image 2, shot from directly below the crossing point, confirms this: it is an open-sky gap with no wire infrastructure anywhere near the embrace.
So the biomechanical puzzle is fully reinstated, and is in fact deeper than before.
What Image 2 actually shows
Looking at it carefully from below — the vine has made a genuine unsupported crossing. The stems are laden with leaves all the way across, which means this is not a wispy trailing end but a load-bearing, self-supporting arc. The leaf density itself adds considerable weight, making the achievement more, not less, remarkable.
A revised structural hypothesis:
The only physically coherent explanation now is that the vine grew along the top of the compound wall first, building its anchored mass there, and then sent out exploratory shoots over the road. These shoots, being young and very light at their growing tips, could extend surprisingly far if the wind was consistently blowing from the wall side toward the tree side — essentially being carried incrementally until a tendril tip made contact with a branch of the tree on the opposite side. Once that first contact was made and gripped, subsequent growth consolidated the bridge.
This makes wind the unsung protagonist of your story — not wires, not human intervention.
The withering observation becomes more significant now — if the far-side tree's branch that anchors the vine is dying or was trimmed, the entire unsupported arc could eventually collapse. It would be worth photographing the anchor point on the tree side if possible.
Me:
I will try to take a picture of the anchoring point.
Later...
Me:
It was not possible to get a picture of the anchor (as you call it) as it was at the other side of the wall. And, the wall completely blocked the view inside of the walled area. However, I found no tree growing higher than the height of the wall, nor any electric pole, just behind the wall. But what can be seen from the third picture, is the thick and verdant growth of the creeper along the wall. At some places, as the creeper went along the wall, offshoots went down towards the pavement below. This can also be seen in the third picture. Perhaps, the wall itself is the 'anchor' of the creeper as it throws itself across the road?
Claude:
This is a brilliant observation, and I think you have cracked it: The wall as anchor — not just support, but launch platform
Look at Image 3 again with fresh eyes. The vine has colonised the entire top of the wall, building up over time a thick, dense, almost continuous mat of growth. This mat is not just resting on the wall — it is gripping it, rooting into its surface, interweaving with itself. The wall has essentially become a living structure, with the vine as its skin.
This changes everything structurally. The vine is not launching from a single point like an arrow. It is launching from a distributed base — a long, anchored, load-sharing platform of its own making. The offshoots you observed going down toward the pavement are also significant: they tell you the vine has so much vigour and mass on the wall that it is sending explorers in every direction — downward, outward, and across.
The crossing then becomes almost inevitable
Once the wall-mat reached the corner or the point closest to the road gap, the vine's natural phototropic drive would send shoots outward into the open sky above the road — the brightest available space. With the entire wall-mat acting as a collective anchor, even a relatively thin shoot extending across could be supported, the way a fishing rod can extend far beyond its handle because the handle is firmly gripped.
What the offshoots going downward tell us:
This is actually the most elegant detail you have noticed. It confirms that the vine is not under any directional compulsion — it is not "trying" to cross the road. It is simply growing in all available directions simultaneously. The crossing is the one that succeeded spectacularly and became visible. The downward offshoots are the forgotten siblings of that same exploratory impulse.
Your instinct is exactly right — the wall is the anchor, the protagonist, and the launch pad all in one. The road crossing is its most dramatic expression.
Me:
I think the loop is not complete. The jury is still out on the motivation of the creeper's leap. Is it growth? Is it try to chart uncharted waters? Is it 'emergence'?
Claude:
You are absolutely right — I was too hasty in declaring the story complete. The how has a reasonable answer now. The why remains genuinely open. Let me lay out the three possibilities you've named honestly:
Is it simply growth?
The reductionist answer. The vine grows because it grows — phototropism, thigmotropism, cell division. No more "motivation" than a river has motivation to flow downhill. This answer is scientifically defensible but feels insufficient, precisely because it explains the mechanism while saying nothing about the outcome — a 50-foot aerial crossing that has persisted for years.
Is it exploration — charting uncharted waters?
This is more interesting. Some botanists and plant behaviour researchers — Stefano Mancuso being the most prominent — have argued seriously that plants make something analogous to decisions, allocating resources toward promising directions and withdrawing from dead ends. The downward offshoots you noticed that found no support and withered — versus the aerial crossing that succeeded and consolidated — could be read as exactly this kind of exploratory trial-and-error. Not conscious, but not purely mechanical either.
Is it emergence?
This may be the deepest framing. The crossing was not planned by any single tendril or any single growth decision. It arose from the accumulation of thousands of small, local, uninstructed growth events — the wall colonisation, the mat formation, the simultaneous multi-directional exploration — producing a global outcome that no single part "intended." That is emergence in its precise meaning.
The jury is indeed still out. And perhaps that is exactly where your blog post should leave it too — not with a tidy answer, but with the question itself held open, respectfully.
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