07-07-2003, 05:02 PM
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"Walking Tree" of Costa Rica. Is it Makainki ?????
In article ,
wrote...
Has anyone looked in AGRICOLA? BRBR
After asking that, I looked myself. There is one article available on stilt
roots in tropical palms.
Further searching revealed that the best-known species of the tropical stilt
rooted palms are
A HREF="http://www.pacsoa.org.au/palms/Iriartea/deltoidea.html" Iriartea
deltoidea/A.
and A HREF="http://www.pacsoa.org.au/palms/Socratea/exorrhiza.html"PACSOA -
Socratea exorrhiza/A
There is no mention anywhere of any of these trees "walking", so the whole
thing may be a myth, like the deadliness of the Upas tree.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)
I also did a database search for (Iriartea or Socratea)
and root*, and at first didn't find much.
Title: ANATOMICAL AND MORPHOLOGICAL STUDY OF THE ADVENTITIOUS ROOTS OF
IRIARTEA-EXORRHIZA THE RASP
PALM AND THEIR GROWTH.
Author, Editor, Inventor: VILHENA-R-C-Q-D {a}; LINS-A; LUNA-M-D-S
ource: Boletim-do-Museu-Paraense-Emilio-Goeldi-Serie-Botanica. 1984
(RECD. 1985); 1 (1-2): 87-110.
Language: PORTUGESE
Abstract: I. exorrhiza is a common palm tree in the Brazilian Amazon
region, remarkable because of its stilt roots. The external morphology,
growth, and anatomy of the aerial stilt roots were studied from the
time of their erupting from the trunk and breaching the bark until they
became anchored in the soil. Chemical analysis of the root tissues and
of the covering mucilaginous secretion were performed. The mucilage
which flows from canals in wounded roots is rich in crystals of calcium
oxalate. The rate of initiation and the growth rate of stilt roots are
correlated with rainfall. Daily growth rate of the roots was 4.13-7.94
cm.
No mention of "walking".
Still, it'd be fascinating if there is a novel mechanism at work
enabling these trees to actually move around, but it sounds like
if so, maybe no-one has studied it?
looking elsewhere, I found
Author(s): Schatz, G.E. ; Williamson, G.B. ; Cogswell, C.M. ;
Stam, A.C.
Title: Stilt roots and growth of arboreal palms.
Source: Biotropica. 17, no. 3 (Sept 1985): p. 206-209. ill.
Additional Info: Fairfax, Va. : Association for Tropical Biology.
Publishing Agencies: US Imprint, not USDA
Abstract: Patterns in the growth of palms support the hypothesis that
stilt roots enable arboreal palms to produce an axis early in their
development. The height of stilt roots is positively related to axis
diameter for Socratea durissima and Iriartea gigantea. Both species
achieve greater heights per unit diameter earlier in development than
the non-stilt root species Welfia georgii;[SNIP]
Talks about the roots function in supporting the plants growth,
but no mention of walking.
But finally, I found this one promising-seeming one:
Author(s): Bodley, J.H. ; Benson, F.C.
Title: Stilt-root walking by an iriarteoid palm Socratea exorrhiza in
the Peruvian Amazon.
Source: Biotropica. Mar 1980. v. 12 (1) : p. 67-71. ill. ISSN:
0006-3606 Additional Info: Fairfax, Va., Association for Tropical
Biology. Publishing Agencies: US Imprint, not USDA
Abstract: The aerial stilt roots of Socratea exorrhiza allow this palm
literally to pick itself up and "walk" out from under fallen limbs and
obstacles that are major hazards for immature palms. The lower trunk
and older roots rot away and are left behind as the tree sends out new
roots and moves away from its germination point.
I just looked at this article, and it's a bit disappointing: the
"walking" is actually quite clearly documented, but its just a
mechanism by which relatively small juvenile palm plants right
themselves after being flattened by falling tree limbs, debris, etc.
The "walking" is just the formation of new stilt roots along the
now-horizontal segmant of the trunk of the flattened young plant,
and the eventual bending upward of the growing tip to form a new
erect trunk. The flattened juvenile "walks" basically by behaving
a bit like a creeping rhizome, then bending upright at the tip and
reestablishing vertical growth a few inches to a few feet away from
the original base of the palm. The righting proces may take years
[the flattened juveniles are reportedly set back in their
development].
So, there's likely no exotic "walking" mechanism involved, just a
knocked-over juvenile palm stem rooting along its length.
Apparently the large adult plants with their prominent stilts
don't use them to walk [at least the article illustrates them but
doesn't mention walking by them].
cheers
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