Palms with taproots

[DoomsDave]

Howdy-u-all:

The thread about Ravenea xerophylla (or however you spell it) got my feeble mind to exercising:

What other palms besides that species have an actual taproot, or at least a taproot like structure?

This isn't the same as a remote-germinating palm that sends down a "sinker" that rises to the surface from which the leaves emerge.

Any one have any thoughts?

[Ken Johnson]

I have seen such discussed in "The Structural Biology of Palms" by Thomlinson. He states (and I am note quoting) that palms first root is different than that of the second and so on but only to then next one, the third.

Some must be easier to study and hence the wierd ones make the list.

Now as to transplanting mature palms...

[Scott]

I thought Braheas and Bizzies have tap roots... am I wrong?

[JayW]

  Scott said:

I thought Braheas and Bizzies have tap roots... am I wrong?

I was also told that Bizmarks have tap roots. I have no idea if that's true or not though.

[LJG]

I do not think any palm has a true tap root.

[Moose]

It depends what your definition is of a tap root.

!. The Genus Borasus I believe has a "tap root", that it why they usually are set back when removed from a container when planting. My opinion is to cut the bottom of the container off, dont worry, the trunk will dispatch the container in time. You can almost forget about transplanting it until it trunks.

2. The Genus Corypha may have a "tap root" as well. They sometimes set back for awhile when removed from a container. Try Borasus technique to plant. Another difficult palm to transplant.

3. The Genus Copernicia may also have a "tap root". They are another difficult Palm to transplant. I have a C. hospita that got leaned over by a hurricane 3 years ago and is just beginning to recover decently. Although at the time it was 13 years in the ground and was beginning to trunk, my theory was the "tap root" got messed with. The palm was leaning at approx. a 22 degree angle. I never tried to right it because of my fear that I would do more root damage.

The three genus mentioned above are difficult to transplant and that is why there are few experts around who make the big bucks moving these specimens. I know that some were righted up after Hurricane Andrew at Fairchild but these we large specimens with many feet of trunk. The "tap root" may not have been as essential at that age not to mention the carbohydrates that these massive trunks must have been storing.

Alas,I am but a palm nerd not an expert, perhaps this would be an interesting question for our Palms publication and its array of distinguished palm mavens.

[Darold Petty]

Len is correct, no palm has a taproot. (refer to 'tap root' and 'fibrous root' at www.widipedia.org )

Palms are monocotyledonous plants and have no cambium. Thus they cannot expand the diameter of the stem, nor the root. Archontophoenix and some other genera can show a marked increase in the stem after vertical elongation but this is the result of existing cells becoming more swollen in size, not new cells. All of the palm roots are adventious and erupt from the base of the stem at their maximum diameter. They can branch to four orders but with each axis order there is an abrupt change in length and diameter (smaller). The mass of roots below the stem resembles a cylindrical brush. The 'saxophone' or 'tillering' habit found in Rhapalostylis, Sabal, Dypsis, and others is a mechanism to embed the base of the stem deeper into the ground. Many of these are difficult to transplant, perhaps leading to the 'taproot' hypothesis.

I would suggest that Dave's plant of Ravenea has the tillering habit (On some palms, the heel is not obvious). Thus the base of the stem axis is below ground and the cells of the stem are grossly swollen by water storage. All of the true roots will erupt from the base of this 'subterranean, swollen, stem base'.

For further reading, consult "Structural Biology of Palms" by P.B. Tomlinson, Oxford University Press, 1990. (Warning, this is heavy reading,... especially for a hobbyist like me! )

[bgl]

Darold,

Thanks a lot for the detailed and interesting explanation! And funny you should mention that book. A couple of months ago someone left this book in our paperbox out by the street. No note, nothing. Have no idea who gave it to me!

Bo-Göran

[DoomsDave]

  bgl said:

Darold,

Thanks a lot for the detailed and interesting explanation! And funny you should mention that book. A couple of months ago someone left this book in our paperbox out by the street. No note, nothing. Have no idea who gave it to me!

Bo-Göran

Why are you so lucky?

[DoomsDave]

  Darold Petty said:

Len is correct, no palm has a taproot. (refer to 'tap root' and 'fibrous root' at www.widipedia.org )

Palms are monocotyledonous plants and have no cambium. Thus they cannot expand the diameter of the stem, nor the root. Archontophoenix and some other genera can show a marked increase in the stem after vertical elongation but this is the result of existing cells becoming more swollen in size, not new cells. All of the palm roots are adventious and erupt from the base of the stem at their maximum diameter. They can branch to four orders but with each axis order there is an abrupt change in length and diameter (smaller). The mass of roots below the stem resembles a cylindrical brush. The 'saxophone' or 'tillering' habit found in Rhapalostylis, Sabal, Dypsis, and others is a mechanism to embed the base of the stem deeper into the ground. Many of these are difficult to transplant, perhaps leading to the 'taproot' hypothesis.

I would suggest that Dave's plant of Ravenea has the tillering habit (On some palms, the heel is not obvious). Thus the base of the stem axis is below ground and the cells of the stem are grossly swollen by water storage. All of the true roots will erupt from the base of this 'subterranean, swollen, stem base'.

For further reading, consult "Structural Biology of Palms" by P.B. Tomlinson, Oxford University Press, 1990. (Warning, this is heavy reading,... especially for a hobbyist like me! )

Thank you!

That's very helpful!

[Scott]

Darold,

Definitely thanks for the explanation. So now - no tap roots for ANY palms.

I have another question... would palm with the 'tillering' habit be more likely to affect nearby walls and other structures? or no? Thanks again for this great explaination!

Scott

[bgl]

Scott,

I would think that any palm that eventually is going to be massive (tillering or not) will also have a relatively aggressive root system, that could potentially cause problems down the road. For me, those have primarily been Roystonea, Clinostigma, Bismarckia and Cocos.

Bo-Göran

[DoomsDave]

  bgl said:

Scott,

I would think that any palm that eventually is going to be massive (tillering or not) will also have a relatively aggressive root system, that could potentially cause problems down the road. For me, those have primarily been Roystonea, Clinostigma, Bismarckia and Cocos.

Bo-Göran

Yeah, I've had to moderate my original pronouncements about "palms will not damage concrete etc" after noting a P. canariensis that cracked a concrete planter apart with its roots.

On the other hand, unlike regular trees, palms do seem to "go with the flow" on physical restrictions, i.e., the trunks tend to mold to walls, rather than knocking them down.

[Darold Petty]

To Scott and Dave; I would say that tillering palms are no more likely than others to affect concrete or structures. Just remember that the tillering palm will produce an adult trunk that is adjacent to the heel at the time of planting. The heel (or saxophone mouthpiece) remains fixed and the trunk diameter will increase only to the one side of the heel. ( a saxophone in profile). I have this very problem in my garden! I planted a Ceroxylon quindiuense in 1983, not aware of the sideways movement. By chance it was oriented the worst possible way and the palm grew directly toward my fence. I now have a palm trunk jammed against the fence, and the fence is distorted about 3 inches sideways by the palm trunk.

Yes, I have observed large palms in concrete planters break the planter walls by the sheer volume of roots. In both cases, the planter volume was unreasonably small for the adult size of the palm species, Phoenix canariensis, and Syagrus romanzoffianum. It is far less likely that a palm can damage a foundation or sidewalk by heaving the concrete vertically. This is because, once again, no cambium, and thus no increase of root diameter. My adult Parajubaea cocoides is just inches from my sidewalk and driveway.

I will try to post a few photos relevant to this discussion tomorrow. Meanwhile,... plant more palms!!!

[DoomsDave]

I cite to Mr. petty's observations to note that some palms

ARE MASSIVELY ROOTY

Ahem!

And, putting them in the wrong spot, is like getting a 500 pound lady to squeeze into that adorable size-2 cocktail dress . . . . .

[Darold Petty]

Here are two photos of my Parajubaea cocoides, planted in 1983. The trunk diameter at the soil line is 58 cm (23 inches) and the distance to the concrete edge on the two sides is about 15 cm (6 inches). Absolutely no heaving of the concrete.... Plant more palms!

[Dave-Vero]

This is an ancient discussion; I found it through a search for "Structural Biology of Palms." This technical book has been available on a custom-print basis from Oxford University Press in England (not the US) at a rather expensive £70, plus shipping. I checked Amazon (US) and found a price of $109.50 and free shipping. That's still expensive, and of course despite Barry Tomlinson being an excellent writer, it's technical. Tomlinson has done wonders in terms of figuring out how palms grow, how their plumbing works, and anything structural. His books will remain valuable to botanists for a very long time.

Now back to taproots. My little Archontophoenix maxima (propagated at Leu Gardens) had been consigned to living in its little pot. When it came time to move it, up came a sturdy, straight "tap root" extending over a foot from the pot. The palm was obviously trying to grow and deserved a permanent home. It took some effort to dig a deep-enough hole.

[pindo]

I agree with Mr Petty.

I think the problem isn't that each root increases in size, but the palm is always issuing new roots, the root ball increases in volume causing structural damage to buildings

Look the following pictures of Syagrus romanzoffiana

[Jastin]

  On 4/15/2009 at 11:41 PM, Darold Petty said:

concrete__Medium_.jpgPcoccoides_sm.jpg

Here are two photos of my Parajubaea cocoides, planted in 1983. The trunk diameter at the soil line is 58 cm (23 inches) and the distance to the concrete edge on the two sides is about 15 cm (6 inches). Absolutely no heaving of the concrete.... Plant more palms!

OH...MY...GOSH! Amazing!

[Cikas]

  On 4/15/2009 at 11:41 PM, Darold Petty said:

concrete__Medium_.jpgPcoccoides_sm.jpg

Here are two photos of my Parajubaea cocoides, planted in 1983. The trunk diameter at the soil line is 58 cm (23 inches) and the distance to the concrete edge on the two sides is about 15 cm (6 inches). Absolutely no heaving of the concrete.... Plant more palms!

Looks great.

[Dave-Vero]

Palms can do a bit of sidewalk-lifting. I've noticed that happening in downtown Fort Pierce with foxtails. But it's minor compared to what woody dicots can do.

Another nice feature of palms is that they always start new roots at the top of the root initiation zone, as explained in this "palm problem" item by University of Florida experts. Because palms replace old roots rather than expand them, palms don't develop the circling roots that can become big problems with dicots such as oaks. It doesn't matter if a container-grown palm has its roots jamming every bit of available space.