Bald cypress "knees"

[Dorky_gearhead]

I did a little poking around on the net and couldn't find anything.

What are they?
Do they produce foliage?
Can foliage be grafted to them?

Just an idea, but if the knees produce branches they could make for an awesome bonsai. They have wicked taper.

Just a thought that's been playing in the back of my head for a while.

Casey

 

[carp]

Knees do not produce foliage but can be thread grafted. I don't think there is any definitive research that states what their precise function is.

 

[Geo]

Read that they were air uptake apparati.Don't remember where.

 

[Zach Smith]

Air uptake, sugar storage, stability, all have been proposed as reasons for BC knees. No definitive answer to date. There has been work done in grafting branches to cypress knees, so this is a viable option if you want to go for it.

Zach

 

[eferguson1974]

Cool idea! How hard are they to collect? And how connected to the tree are they? Ive seen them standing in water but dont remember them on dry land much. Maybe because it was flooded or maybe I just dont remember. Sounds like a good head start, using knees. Hope it works out, Id like to see when its ready...good luck!

 

[Dorky_gearhead]

Cool idea! How hard are they to collect? And how connected to the tree are they? Ive seen them standing in water but dont remember them on dry land much. Maybe because it was flooded or maybe I just dont remember. Sounds like a good head start, using knees. Hope it works out, Id like to see when its ready...good luck!

From what I've read the knees occure in wet soil. It does happen on "dry" land but the earth is far from dry.

Unfortunately I'm nowhere near the swamps where bald cypress are native to

 

[Jarath]

The knees are the root system of a bald cypress. They are known for shallow roots and the knees stabilize the tree.

 

[M. Frary]

I don't think there is any definitive research that states what their precise function is.

So their legs can bend!

 

[Zach Smith]

The knees are the root system of a bald cypress. They are known for shallow roots and the knees stabilize the tree.

The knees are NOT the root system of a bald cypress, else those with few to none growing on dry land would not have a root system at all and could not survive. Knees are merely protuberances from the root system with no scientifically definitive function - unless you can cite for us the new research on the subject that puts the question to bed. See Baldcypress: The Tree Unique, The Wood Eternal by Dr. Clair A. Brown and Glen N. Montz, page 94.

Incidentally, I have stood inside a hollowed out (living) ancient bald cypress with knees emerging from the ground inside the hollowed out bole that were nearly my height. A pretty wicked experience.

Zach

 

[GGB]

DUDE! what a wicked idea. that seems perfect on paper. If I lived further south I would totally try this myself. Please post updates. I think you're onto something.

 

[Jarath]

Cypress knees are considered Pneumatophores
. These are considered aerial roots. Some scientists believe they oxygenate the roots and stabilize the tree in swampy conditions. So I would consider them part of the root system. Right?

 

[Zach Smith]

Here's the best I can do for you, then come to whatever conclusion you want: From Baldcypress: The Tree Unique, The Wood Eternal, by Clair A. Brown and Glen N. Montz, page 96 - "Most early researchers believed that knees acted as breathing organs (Dickeson and Brown, 1848; Lamborn, 1890; Shaler, 1887; Wells, 1942; and Wilson, 1889). Others did not completely accept the fact that knees exchanged gases as there was no proof (Kurz and Demaree, 1934; Mattoon, 1915; Oosting, 1956; and Penfound, 1934). After extensive studies, Kramer, Riley and Bannister (1952) concluded that little gas exchange occurred between knees and the root systems on which they occur, and there was no evidence that they play an essential role as aerating structures for the roots." Also, studies of BC on dry land have shown little susceptibility to wind-throw (Penfound, 1952), therefore the knees are not needed for stability. There's a lot more in this section of the book, including research done by the senior author. His conclusion was that the most plausible and provable function of the knee was starch storage.

Zach

 

[Jarath]

So they are part of the root system? I found much of the same as you did. It seems nobody has any understanding what their purpose is.

 

[ysrgrathe]

No one knows. As Zach referenced, it seems unlikely that they are involved in respiration. Some propose that they exist to stabilize the tree (as Jarath noted) since they occur more frequently in wet, unstable soils.

 

[Mellow Mullet]

I just think that they are something that the tree does, like make bark, leaves, branches, etc. The have no particular purpose, just a characteristic of the bald cypress. Just as some trees make thorns, prickly ash for example, or others make thorns; there is no reason for it, just part of the charm for that species. They could not possibly stabilize a tree, as they are above ground, that makes no sense. They also occur just as frequently in regular soil as they so in wet soil. They are used for landscaping here a lot and it is not uncommon to see them with knees in yards, makes grass cutting a PIA. The local Home Depot has them in their parking lot and most have knees. There is no mystery, bald cypress just make knees.

John

 

[sorce]

So their legs can bend!

And they can pray these MF's stop digging em up! Hey....you are MF!

________

Seriously......

I wonder if they ever checked their height against flood levels?

It's possible the tree sends them up to remain above a normal flood line, So if it ever needs to, it can sprout new growth above water borne vegetarians.

It applies well to the 2 stands I know of.

In evolutions grand scheme...it makes sense for it to be a deciduous conifer to do this.

It also makes perfect sense we would have never seen them grow shoots, they haven't needed to yet.

Sorce

 

[choppychoppy]

here is a knee with a thread graft

 

[ysrgrathe]

There is a literature review here:
http://arnoldia.arboretum.harvard.edu/pdf/articles/2000-60-4-cypress-knees-an-enduring-enigma.pdf

 

[0soyoung]

So, @Mellow Mullet, you have a lot of experience with bald cypress. Have you ever cross sectioned a knee to see what its like inside?

... just curious.

 

[Mellow Mullet]

So, @Mellow Mullet, you have a lot of experience with bald cypress. Have you ever cross sectioned a knee to see what its like inside?

... just curious.

I have, it is woody, like the rest of the tree. When I repotted the clump last year, I had to cut a root shorter that had a knee growing on it. I think that there is a picture of it in the thread. The knees grow from the tops of the roots that are just below the surface of the soil. Nothing really special about their make up. around here I have seen lamps and tables made of them.