In article , [P
van Rijckevorsel] wrote...
"This tree is known as the 'walking tree' because it can move. If the
tree needs to move, it just grows roots on that side and lets other roots
die.

Iris Cohen schreef

I looked at the pictures. It is up on these weird stilt roots, something
like a mangrove. You can easily imagine it growing one root at a time in
the direction of more food or water, and one root at a time dying off on the
other side. Look, if a Welwitschia works, no reason why this can't.
Iris,

But Welwitschia, odd as it is, stays in one place.

+ + +
I can think of reasons why it wouldn't work, but I would not preclude that
it may work. All those pictures show plants on hillsides so they would tend
to move downhill. I don't know enough about stilt roots of palms to say
anything sensible.

It has been shown time and again that truth is stranger than fiction, so who
knows?

How can the palm move anywhere if the older stilt roots still remain
anchored in the ground and don't actually disintegrate [the photos
seem to clearly show that they don't]? They're "woody", strong and
tough, not at all stretchy. To "walk" the tree might be expeced to
pick up its feet.

And even if all the older roots did die away as described above
[again,not shown in any of the photos] how would the formation of
new stilt roots cause the tree to move directionally, if they don't
forcibly contract after penetrating the ground? They would just
continue to prop it in its original place.

Maybe a tree something like this could move along while standing
erect if the stilt roots on the "moving toward" side are highly
contractile and exerting powerful tensile forces that are being neatly
balanced by similar pulls by most of the other stilt roots, while those
roots on the "moving away from" side gradually yield and let go, all of
them continually being lost and replaced by later-formed roots.

But then, the whole stilt root systems of the tree wouldn't look much
like the ones in in the photos. These look like sturdy permanent props,
not a system of short-lived taught cables that could be pulling the
tree along "hand over hand". And again, the early-formed stilt roots
still appear to be firmly rooted; they evidently aren't being uprooted
and dragged along the ground...

I'll bet these palms really don't even budge [apart from during
earthquakes and landslides].

For a weird plant that really does make tracks, a favorite example is
the "creeping devil" cactus from Baja California [Stenocereus eruca or
Machaerocereus eruca]. The large prostrate rooting stems have a typical
cactus growing tip at one end and continually die away at the basal end,
so the thing looks like a big spiny caterpillar as it roots its way
along ["eruca" means "caterpillar"]:

http://www.desert-tropicals.com/Plan...eus_eruca.html
http://cactiguide.com/graphics/s_eruca_b_600.jpg
http://www.hortpix.com/pc4100.htm
http://cactiguide.com/Stenocereus.htm

cheers