# Twisted Trees (No, not that kind.) **URL:** \ **Category:** Factual Questions\ **Created:** [August 13, 2009, 7:50pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325 "2009-08-13T19:50:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [August 13, 2009, 7:50pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/1 "2009-08-13T19:50:51Z")
I posted this question on science type message board and didn’t get any replies that satisfied me. I know, I know - I should have come here first. Anyway, here it is: I’ve observed that trees often have “twist” to their trunks. It looks like someone grabbed them by the top and twisted them as they were growing. It seems the twist is usually (maybe always) counter-clockwise if viewed from the top. Its easy to see on dead trees and may or may not always be some type of evergreen, I just haven’t taken the time to note the species. Why the twist? Why always the same direction? Ideas from the other board included wind patterns and the coriolis effect. I’m not conviced of either one. Dopers? ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [August 13, 2009, 7:59pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/2 "2009-08-13T19:59:31Z")
The tree, as it grows, always has a number of forces acting on it, including gravity, wind, prevailing winds, direction of sunlight, slope of land, etc. So it doesn’t get a chance to grow in perfect environs. Something is always mildy torquing it’s trunk, even the non-perfect distribution of branches and the resulting branch load. Combined with even mildy-sloping ground, prevailing winds and inconsistent rains and branch loads, a slight twist would be expected. This is not a total WAG, but is me recounting some of what I’ve been told when I had trees inspected around my property. Some trees are more vulnerable, too. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 13, 2009, 8:26pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/3 "2009-08-13T20:26:30Z")
Sorry, no cite, but I’m pretty sure that some plants tend to exhibit spiral growth regardless of the prevailing conditions - and that it’s just inherent to their growth behaviour (like people having curly hair, I guess). In the case of trees like sweet chestnut, I think it makes the trunk stronger or better able to cope with flexing. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [August 13, 2009, 8:52pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/4 "2009-08-13T20:52:54Z")
> [@MikeF](#): > > Why the twist? Why always the same direction? This high school teacher seems to have a pretty good handle on [twisting in bristlecones:](http://drake.marin.k12.ca.us/staff/wing/WMRS_Bristlecones.htm) > [@](#): > > Nobody seems to understand twisting in bristlecone pines, or in any other tree species for that matter. (Twisting is not limited to bristlecones.) There are a number of hypotheses that get repeated: > > ``` > 1) It's "just genetics" - twisting confers no particular advantage to the tree, and is not caused by environmental factors. Sort of like handedness in humans. Tree twisting should not correlate with environmental factors. > > 2) Twisting makes the trunk stronger and more resistant to breakage. If that were so, we would expect to find proportionallly more dead and/or broken tree trunks that are straight, and more living/unbroken trees that are twisted. > > 3) Phototropism: Just as sunflowers track the sun's daily progress across the sky, so do trees. This causes twisting. The twisting should be counter-clockwise as you look up the tree trunk. Trees with views of the western and eastern horizons blocked by ridges should exhibit less twisting. > > 4) Torque from prevailing winds: Since there is more foliage on the sunny (south) side of the tree, the prevailing (westerly) winds push on that foliage and twist the tree. The twisting should be clockwise as you look up the trunk. Sheltered trees should exhibit less twisting. > > ``` > > Surprisingly, all of these hypotheses can be tested without doing genetics. We just need to survey a large sample of trees and use statistics. In the spring of 2010 Drake Students will begin a twisting survey of bristlecone pines. I expect that the correct answer depends on the species under consideration. In your case, hypothesis 3, Phototropism, sounds promising. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 13, 2009, 9:07pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/5 "2009-08-13T21:07:42Z")
If it’s phototropism, comparing trees of the same species planted in opposite hemispheres should be useful. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [August 13, 2009, 9:18pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/6 "2009-08-13T21:18:13Z")
I agree with Squink re: actual twists, but I don’t see those very often. WAG Is it possible that what you’re actually seeing is the result of a vine that grew on the tree and then died? They leave a very distinctive spiral whorl in the bark. ---
**Author:** ![janeslogin](https://avatars.discourse-cdn.com/v4/letter/j/df788c/32.png) [@janeslogin](https://boards.straightdope.com/u/janeslogin)\ **Post date:** [August 13, 2009, 9:25pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/7 "2009-08-13T21:25:55Z")
> [@Mangetout](#): > > Sorry, no cite, but I’m pretty sure that some plants tend to exhibit spiral growth regardless of the prevailing conditions There is quite a bit of twisting in the botanical world. You can see this up close in the pattern in the petals on some flowers, in the pattern of the formation of sunflower seed etc. I don’t know how much this is the primary factor in trees and how much the other forces e.g. wind etc. are secondary acting upon these tendencies to twist. ---
**Author:** ![schnuckiputzi](https://avatars.discourse-cdn.com/v4/letter/s/ecb155/32.png) [@schnuckiputzi](https://boards.straightdope.com/u/schnuckiputzi)\ **Post date:** [August 13, 2009, 9:46pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/8 "2009-08-13T21:46:15Z")
When we were hiking up in the Rocky Mountains, we would see pine trees (no clue species) that were twisted around completely several times, due to the prevailing winds whipping around the side of the mountain (according to the ranger). ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [August 14, 2009, 3:23pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/9 "2009-08-14T15:23:51Z")
So far, it sounds like nobdy really knows for sure. The phototropism theory sounds sort of good but why would the twist be clockwise (and it is) as you look up? North of the equator the sun traverses the southern sky. If the tree was twisting to follow it wouldn’t the twist be counter clockwise? Also the twisting I seen is pretty uniform - to the point where environmental causes seem unlikely. I don’t like the wind idea for several reasons, although it would give the correct direction of the twist. I find it hard to believe that that much torque could be exerted. The branches should have the most drag near ther tips where most of the leaves/needles are located. But it is here that they are the most flexible and they can simply bend with the wind. Second, if the wind was exerting that much force, the branches that are coming around the north side as the tree twists would also be subjected to these same forces. One could argue that they are smaller than the branches on the south side and, therefore, subject to less drag. But how much smaller are they, really? Any smaller at all? To discount the “twist is stonger” idea by saying we should see more dead straight trees and more live twisted trees is a mistake. I think is simply easier to observe the twist on dead trees due to lack of foilage and braches being broken off near the trunk. The dead trunks dry out and split along the grain making the twist plain to see. These trees didn’t necessarily die due to being snapped off but from insects or fire or whatever. The more I think about it, the more I think it has been pine trees I’ve seen this in. This may be one for the Great One himself. Cecil? ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [August 14, 2009, 3:44pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/10 "2009-08-14T15:44:00Z")
OK, I’m curious. What kind of “twisted trees” were being referred to in the title (“No, not that kind.”)? ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [August 14, 2009, 4:02pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/11 "2009-08-14T16:02:23Z")
> [@Dewey\_Finn](#): > > OK, I’m curious. What kind of “twisted trees” were being referred to in the title (“No, not that kind.”)? I’m stumped. I think the consideration of damage to a spot on the trunk leading to irregular tension as the tree grows needs to be brought up. This could be something as simple as a large rock rubbing against it when it was younger, or an animal damaging the trunk. There are also twisted trees that were twisted by tornadoes and ice accumulation. They never straighten out after the event. Damage to the interior of the tree will affect the growth of the trunk and may not show on the outer bark. This damage can be animal, insect, disease, fungus, a dead branch healed over, water damage, mineral toxicity. or mechanical like a bullet or nail embedded under the healed bark. Those are all something that can distort a tree trunk, and I know I didn’t cover every possibility. Don’t forget lightning strikes. ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [August 14, 2009, 4:38pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/12 "2009-08-14T16:38:02Z")
> [@Dewey\_Finn](#): > > OK, I’m curious. What kind of “twisted trees” were being referred to in the title (“No, not that kind.”)? Marijuana, probably. “Trees” is a relatively uncommon (around here) way to refer to pot, and I assume “twisting” might have something to do with rolling a joint. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [August 14, 2009, 4:40pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/13 "2009-08-14T16:40:09Z")
> [@MikeF](#): > > So far, it sounds like nobdy really knows for sure. If definitive answers are out there, I expect they’re buried deep within someone’s PhD dissertation, or at best printed in the ‘montana journal of obscure botanical conundrums’. ---
**Author:** ![Snickers](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Snickers](https://boards.straightdope.com/u/Snickers)\ **Post date:** [August 14, 2009, 4:42pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/14 "2009-08-14T16:42:02Z")
> [@Dewey\_Finn](#): > > OK, I’m curious. What kind of “twisted trees” were being referred to in the title (“No, not that kind.”)? Well, there’s definitely a “twisted” tree in Evil Dead 2. There’s also some arborist artists that specialize in creating living art by growing trees using various contraptions and restraints, twisting them around on themselves and creating spiral shapes and such. I think the OP is referring to trees other than these kinds, trees he’s seen that just seem to naturally twist while growing. ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [August 14, 2009, 7:01pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/15 "2009-08-14T19:01:36Z")
Yes, I was referring to marijuana. Around here (Southern New Jersey) “trees” is common slang for that most evil of all weeds. At least it was when I was a narcotics cop a few years ago. Now I’m retired and have time to ponder things such as those that appear here daily. ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [August 14, 2009, 7:59pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/16 "2009-08-14T19:59:58Z")
The degree of the twisting is [related](http://www.google.com/search?hl=en&q=fibonacci+plants&sourceid=navclient-ff&rlz=1B3GGGL_enUS241US242&ie=UTF-8&aq=t&oq=fibonacci+plants)to the Fibonacci sequence. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [August 14, 2009, 9:33pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/17 "2009-08-14T21:33:04Z")
Some trees are just [plain evil.](http://farm3.static.flickr.com/2123/2149426957_606d74d08f.jpg?v=0) ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [August 14, 2009, 10:54pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/18 "2009-08-14T22:54:45Z")
If anyone wants to pony up the $28 for access, you may find the answer [here](http://jhered.oxfordjournals.org/cgi/reprint/23/2/49) (link is to a paper entitled “What Causes Twisted Trees?”, from the Journal of Heredity. The paper was published in 1932. So, either he got it wrong and folks are still debating the cause(s), or nobody’s ever read the paper 😉 ). ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [August 14, 2009, 11:14pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/19 "2009-08-14T23:14:25Z")
> [@Darwins\_Finch](#): > > If anyone wants to pony up the $28 for access, you may find the answer [here](http://jhered.oxfordjournals.org/cgi/reprint/23/2/49) (link is to a paper entitled “What Causes Twisted Trees?”, from the Journal of Heredity. The paper was published in 1932. Searching for a free copy lead me to this, from 2004: [http://www.springerlink.com/content/t6588m24684238v3/](http://www.springerlink.com/content/t6588m24684238v3/) > [@](#): > > Function of spiral grain in trees > Journal Trees - Structure and Function > … > Through spiral grain, conduits for sap lead from each root to all branches. This uniform distribution of sap is indicated by the paths of vessels and tracheids, and has been proven experimentally by means of dyed sap injected into the base of stems or taken up by roots. Trees receiving water only from roots at one side of the root collar nevertheless stay green and continue growing. Spiral grain in bark distributes food from each branch to other flanks of the stem and to most roots. Experimental interruptions of the sap… > > Although spiral grain is largely under genetic control, trees appear to have a spiral grain especially where needed for distribution of water when root spheres are dry at one side. Compared with straight-grained trees, spiral-grained stems and branches bend and twist more when exposed to strong wind, in this way offering less wind resistance and being less likely to break. Through the bending and twisting, snow slides down from branches rather than breaking them, but the main function of spiral grain is the uniform distribution of supplies from each root to all branches, and from each branch to many roots. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [August 14, 2009, 11:16pm UTC](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325/20 "2009-08-14T23:16:26Z")
> [@Dewey\_Finn](#): > > OK, I’m curious. What kind of “twisted trees” were being referred to in the title (“No, not that kind.”)? > [@MikeF](#): > > Yes, I was referring to marijuana. Around here (Southern New Jersey) “trees” is common slang for that most evil of all weeds. At least it was when I was a narcotics cop a few years ago. Now I’m retired and have time to ponder things such as those that appear here daily. Thank you. [Next page](https://boards.straightdope.com/t/twisted-trees-no-not-that-kind/506325.md?page=2)