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Trees that sucker from the roots
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Posted by TonyfromOz z10 NSW Aust (My Page) on Wed, Mar 30, 05 at 4:14
| Can anyone enlighten me on the anatomical and/or physiological mechanisms that underlie this phenomenon, well known in certain trees - for example tree-of-heaven, some elms, Lombardy and white poplars. I can't find any reference to it in my (admittedly old) anatomy or morphology textbooks, or by a Google search.
I have always assumed that the suckers come from true roots, which when stimulated in certain ways (cutting of roots, rising water table?) are able to produce somewhere in their tissues some sort of anomalous meristem that can produce stem tissue. This ability to produce stems from the root system is certainly not found in the vast majority of trees.
I guess the alternative explanation would be that the 'roots' of such trees, or at least parts of their root systems, are not roots at all but underground stems. This seems unlikely to me. When you dig them up they look just like roots - in contrast to the true underground stems of plants such as bamboos, raspberries or mints. |
Follow-Up Postings:
RE: Trees that sucker from the roots
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| All of my un-scientific reasoning, based upon my sole observations, suggests a very active root system. Suckering can occur also in the form of "shoots" from the trunk. It was my understanding that a sucker was a shoot and not a stem, hence sucker. I'm still waiting to see how my willow sucker transplants "whips" will do this season. |
RE: Trees that sucker from the roots
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| Here's a little reading, it seems to have a few ideas: http://www.sacbee.com/static/archive/home/gardening/garden_detective/2001/0908a.html |
RE: Trees that sucker from the roots
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- Posted by tapla z5b-6a MI (My Page) on
Sun, Apr 10, 05 at 18:37
| My take: Many woody plant species have dormant buds in stem and or root tissues, at or below soil surface. Frequently, the highest density of these buds is found at the root collar (or basal flare), but many species contain these buds in roots near the surface. In a normally growing tree, the hormones auxin and cytokinin have something of an antagonistic relationship, with the auxin stimulating apical growth and suppressing cytokinin's stimulation of lateral or secondary (to apical) meristems. Without getting too complicated here by getting into branching index, it should suffice to say that anything suppressing the flow of auxin will normally stimulate dormant buds. Since auxin is produced in apical meristems and leaves, tree injury (including pruning) that reduces auxin production and its suppression of dormant buds allows cytokinin induced activation of the buds. Of course, we would look first to pruning, especially improper (as in tip pruning) or heavy pruning as causal. A few other causes might be insects, wind damage, disease pathogens, cold injury, etc. Al |
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