# Weeds the size of trees **URL:** \ **Category:** Factual Questions\ **Created:** [June 27, 2010, 11:04pm UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724 "2010-06-27T23:04:05Z")\ **Posts on this page:** 8\ **Page:** 2
**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:** [June 28, 2010, 9:02pm UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/21 "2010-06-28T21:02:09Z")
Japanese knotweed is an invasive herbaceous plant that may grow 8ft tall or more (comparable to the size of saplings) - and has hollow stems. Alternatively, Elder (Sambucus spp) is a tree in the proper (common) sense, but has stems that may be hollow or filled with soft pith. Actually, there are quite a few plants that might reasonably grow to something called a tree, and might have hollow-ish stems. Forsythia and philadelphus are another couple. ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [June 28, 2010, 10:32pm UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/22 "2010-06-28T22:32:01Z")
Several of y’all seem to be ignoring the “hollow stem” part of the OP. 🙂 Just how tall _were_ these tree-like weeds? Also, where were they, geographically? [Jimson](http://www.remedydevices.com/page3/datura.jpg) [weed](http://www.richters.com/Web_store/Html/Images/X6060.jpg) has a hollow stem and can get to be pretty dang tall. The aforementioned [poke](http://nbii-nin.ciesin.columbia.edu/ipane/images/P8290002.JPG)[weed](http://www.bing.com/images/search?q=pokeweed&go=&form=QBIR&qs=n&sk=&sc=8-8#focal=989fce884a974d5f0425538e00bcc95d&furl=http%3A%2F%2Fwww.duke.edu%2F~jspippen%2Fplants%2Fphytolacca-americana080908-1986durhamz.jpg) also grows pretty tall. It has a stem with a spongy center. ---
**Author:** ![cainxinth](https://avatars.discourse-cdn.com/v4/letter/c/7bcc69/32.png) [@cainxinth](https://boards.straightdope.com/u/cainxinth)\ **Post date:** [June 29, 2010, 3:34am UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/23 "2010-06-29T03:34:43Z")
> [@spoke-](#): > > Several of y’all seem to be ignoring the “hollow stem” part of the OP. 🙂 > > Just how tall _were_ these tree-like weeds? Also, where were they, geographically? I couldn’t say how tall they were, looked like 50 feet at least. Geographically, they were growing in a vacant lot in north Philadelphia. ---
**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:** [June 29, 2010, 9:34pm UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/24 "2010-06-29T21:34:19Z")
50ft?! I withdraw everything I suggested. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [June 29, 2010, 9:40pm UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/25 "2010-06-29T21:40:31Z")
> [@Mangetout](#): > > 50ft?! > > I withdraw everything I suggested. Yes, that’s pretty sizeable for a hollow stem. However: > [@](#): > > [Many prehistoric bamboos exceeded heights of 85 metres](http://en.wikipedia.org/wiki/Bamboo) (279 ft) [citation needed]. Primarily growing in regions of warmer climates during the Cretaceous period, vast fields existed in what is now Asia. Perhaps some sort of temporal rift has opened… ---
**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:** [June 29, 2010, 9:43pm UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/26 "2010-06-29T21:43:42Z")
Sure, even extant bamboos can get pretty big, but it just doesn’t seem all that likely someone would describe them as weeds that look like trees. ---
**Author:** ![elelle](https://avatars.discourse-cdn.com/v4/letter/e/f0a364/32.png) [@elelle](https://boards.straightdope.com/u/elelle)\ **Post date:** [June 30, 2010, 12:14am UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/27 "2010-06-30T00:14:33Z")
In common use, “weeds” refer to herbaceous plants, but, as said, any nuisance plant can be considered a weed. The better term for an out of control tree would be “invasive”. [Here’s](http://weeds.cas.psu.edu/invasive_plants.html#non_native_trees) a site from Penn State that details invasive plants, with plenty of links. Maybe you can find the “tree” you’re looking for there. If you can describe the leaves, trunk, and perhaps flowers, I can probably help you narrow down the ID. ---
**Author:** ![Hello\_Again](https://avatars.discourse-cdn.com/v4/letter/h/85e7bf/32.png) [@Hello\_Again](https://boards.straightdope.com/u/Hello_Again)\ **Post date:** [June 30, 2010, 2:28am UTC](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724/28 "2010-06-30T02:28:01Z")
If its as big as all that, it’s almost definitely an Ailanthus. A true, and disturbingly hardy, tree. I was looking up ways to kill it and found this link: [http://www.nps.gov/plants/alien/fact/aial1.htm](http://www.nps.gov/plants/alien/fact/aial1.htm) which among other things, suggests powerful herbicides _mixed with fuel oil, gasoline, or diesel_. Yikes. [Previous page](https://boards.straightdope.com/t/weeds-the-size-of-trees/544724.md?page=1)