Last week I encountered a patch of stinging nettle and had my hand
irritated for some hours. For those
unaware of stinging nettle, it is a plant with needles on its stem and
tipped with acid so as the
hand or legs brush against this nettle, the skin is irritated.

I have a question on stinging-nettle. What animal caused the evolution
of this stinging plant? Is it grazing animal
such as rabbits or some hoofed grazer? I tend to think stinging nettle
evolved because of the prescence
of humans? I wonder if stinging nettle is due solely to the prescence
of humans? That planet Earth would
not have stinging nettle if not for humanity. And whether there are
biological firsts for stinging-nettle and
Homo sapiens.

Question: is that true? Second question: If true then how old is this
co-evolving relationship?

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies

"a_plutonium" wrote in message
ups.com...
Last week I encountered a patch of stinging nettle and had my hand
irritated for some hours.

Ouch!

For those
unaware of stinging nettle, it is a plant with needles on its stem and
tipped with acid so as the
hand or legs brush against this nettle, the skin is irritated.

Not exactly. The hairs are actually like stiff little hypodermic
needles with glassy walls and a tip that neatly snaps off on contact
so that the hair's contents are injected into the tiny wound the
hair makes.

I have a question on stinging-nettle. What animal caused the evolution
of this stinging plant? Is it grazing animal
such as rabbits or some hoofed grazer?

Why not both, or potentially plant-damaging animals in general? The
tiny needles with painful nerve-stimulating juice inside might work
just as well on almost any animals. This article suggests that the
stinging hairs defend against mammals but not insects:

http://www.jstor.org/view/00301299/ap060198/06a00120/0

I tend to think stinging nettle
evolved because of the prescence
of humans? I wonder if stinging nettle is due solely to the prescence
of humans?

Why humans? There seems to be no reason to think the nettle's stinging
hairs have evolved in any specific relationship with humans. There are
plenty of other animals out there to be stung.

That planet Earth would
not have stinging nettle if not for humanity. And whether there are
biological firsts for stinging-nettle and
Homo sapiens.

Question: is that true?

Again, why think it has anything specific to do with humans?

Second question: If true then how old is this
co-evolving relationship?

The stinging-hairs type of defense has evolved independently in
several different groups of plants. Even in true nettles [family
Urticaceae] there are numerous stinging species in several genera
as well as many non-stinging genera.

http://en.wikipedia.org/wiki/Urtica
http://en.wikipedia.org/wiki/Stinging_nettles
http://en.wikipedia.org/wiki/Dendrocnide
http://en.wikipedia.org/wiki/Dendrocnide_moroides

Besides "true" nettles, there are similarly very nettle-like stinging
plants in the Euphorbiaceae [e.g., Tragia, Cnidosculus] the Loasaceae,
and perhaps some other families.
e.g:
http://waynesword.palomar.edu/wigandia.htm

Many other plants have other sorts of irritating hairs that likely
also play a defensive role.

Some of these adaptations are undoubtedly fairly old [in true nettles,
cladistic analyses may tell us whether stinging hairs would have been
present in the last common ancestor of all modern stinging Urticaceae].

One neat thing worth pointing out is that nettles and similar plants
are genuine examples of _venomous_, not merely poisonous, plants.

cheers

I have a question on stinging-nettle. What animal caused the
evolution of this stinging plant? Is it grazing animal such
as rabbits or some hoofed grazer?

Caterpillars, perhaps?

============== j-c ====== @ ====== purr . demon . co . uk ==============
Jack Campin: 11 Third St, Newtongrange EH22 4PU, Scotland | tel 0131 660 4760
http://www.purr.demon.co.uk/jack/ for CD-ROMs and free | fax 0870 0554 975
stuff: Scottish music, food intolerance, & Mac logic fonts | mob 07800 739 557

On Mon, 06 Aug 2007 01:47:14 +0100, Jack Campin - bogus address
wrote:

I have a question on stinging-nettle. What animal caused the
evolution of this stinging plant? Is it grazing animal such
as rabbits or some hoofed grazer?

Caterpillars, perhaps?

============== j-c ====== @ ====== purr . demon . co . uk ==============
Jack Campin: 11 Third St, Newtongrange EH22 4PU, Scotland | tel 0131 660 4760
http://www.purr.demon.co.uk/jack/ for CD-ROMs and free | fax 0870 0554 975
stuff: Scottish music, food intolerance, & Mac logic fonts | mob 07800 739 557


deer

mel turner wrote:
"a_plutonium" wrote in message
ups.com...
Last week I encountered a patch of stinging nettle and had my hand
irritated for some hours.

Ouch!

For those
unaware of stinging nettle, it is a plant with needles on its stem and
tipped with acid so as the
hand or legs brush against this nettle, the skin is irritated.

Not exactly. The hairs are actually like stiff little hypodermic
needles with glassy walls and a tip that neatly snaps off on contact
so that the hair's contents are injected into the tiny wound the
hair makes.

I have a question on stinging-nettle. What animal caused the evolution
of this stinging plant? Is it grazing animal
such as rabbits or some hoofed grazer?

Why not both, or potentially plant-damaging animals in general? The
tiny needles with painful nerve-stimulating juice inside might work
just as well on almost any animals. This article suggests that the
stinging hairs defend against mammals but not insects:

http://www.jstor.org/view/00301299/ap060198/06a00120/0

I tend to think stinging nettle
evolved because of the prescence
of humans? I wonder if stinging nettle is due solely to the prescence
of humans?

Why humans? There seems to be no reason to think the nettle's stinging
hairs have evolved in any specific relationship with humans. There are
plenty of other animals out there to be stung.

That planet Earth would
not have stinging nettle if not for humanity. And whether there are
biological firsts for stinging-nettle and
Homo sapiens.

Question: is that true?

Again, why think it has anything specific to do with humans?

Second question: If true then how old is this
co-evolving relationship?

The stinging-hairs type of defense has evolved independently in
several different groups of plants. Even in true nettles [family
Urticaceae] there are numerous stinging species in several genera
as well as many non-stinging genera.

http://en.wikipedia.org/wiki/Urtica
http://en.wikipedia.org/wiki/Stinging_nettles
http://en.wikipedia.org/wiki/Dendrocnide
http://en.wikipedia.org/wiki/Dendrocnide_moroides

Besides "true" nettles, there are similarly very nettle-like stinging
plants in the Euphorbiaceae [e.g., Tragia, Cnidosculus] the Loasaceae,
and perhaps some other families.
e.g:
http://waynesword.palomar.edu/wigandia.htm

Many other plants have other sorts of irritating hairs that likely
also play a defensive role.

Some of these adaptations are undoubtedly fairly old [in true nettles,
cladistic analyses may tell us whether stinging hairs would have been
present in the last common ancestor of all modern stinging Urticaceae].

One neat thing worth pointing out is that nettles and similar plants
are genuine examples of _venomous_, not merely poisonous, plants.

cheers

Thanks for the long and detailed discussion. I am wondering how far
back
the stinging nettle lines go in history. Whether they existed before
humanity
existed.

I noticed the cat eating some nettle in springtime, unless I have it
confused
with wild mint. So maybe cats enjoy the nettle acid tipped needles.

I notice my horse, donkey and Llama refuse to eat nettle. Even when I
try
to place nettle before an apple where they refuse to bite into the
nettle. Maybe
the donkey ate some nettle, not sure of that fact?

What I am guessing from my potato patch next to a cucumber patch where
the grasshoppers mowed down the potato leaves but left the cucumber
untouched.

I am guessing that stinging nettle co-evolved with grasshoppers. And
the nettle is
targeting grasshoppers. But I would need some understanding as to how
nettle
hyperdermic needles penetrate a grasshopper or ward off grasshoppers.

The positioning of the needles appears to be a position targeting
grasshoppers.

But grasshoppers mostly have a hard crusted body so how would the acid
of the
nettle play into the grasshoppers body?

Is the age of the nettle classes about the same in historic time--
hundreds of million
of years as the age of grasshoppers? So is there some geological time
age of nettles
that closely follows the time age of grasshoppers?

Obviously if nettles go back hundreds of million years then human
species was not
the evolutionary impetus, but if grasshoppers follow a similar time-
line, then it is grasshoppers
that are the intended victims for stinging nettle.

What I am trying to do is find out the "intended victims" for stinging
nettle.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies

A.E.Housman has a nettle poem, in fact
http://famouspoetsandpoems.com/poets...an/poems/14086

--


On the internet, nobody knows you're a jerk.

According to this website of a team of researchers:

Responses of Invertebrate Herbivores to Stinging Trichomes of Urtica
dioica and Laportea canadensis
Tracey D. Tuberville, Peter G. Dudley, A. Joseph Pollard
Oikos, Vol. 75, No. 1 (Feb., 1996), pp. 83-88
doi:10.2307/3546324
This article consists of 6 page(s).

They hypothesized that Urtica evolved more as a response to mammals
than to insects.

But I do not see how Urtica can penetrate the thick hides of most
grazing animals. I doubt that
stinging nettle would penetrate deer or buffalo.

As for mice and rodents, they would not do enough damage to the plant
to bother with.

So that leaves insects such as swarms of grasshoppers.

So I would have my bets not on mammals but insects and especially
grasshoppers.

Unless the stinging nettle works on the mouth and tongue of a mammal.
For humans it
would be the skin, since we are not eating nettle. So maybe it is the
mouth and tongue
of mammals that the nettle is targeting.

And then, of course, the evolution of the nettle was to ward off all
herbivores be they
mammals or insects.

Maybe the chemicals involved tell us who the targeted victims are?
Some say histamine
and acetocholine and folic acid are involved. So does anyone know if
these chemicals
target the mouth of a mammal or the mouth of a insect?

Perhaps the toxic chemicals involved tell us which mammals and insects
co-evolved with
stinging nettle.

Maybe the chemicals were not designed to penetrate grazing mammals but
were designed
for scent so that a deer or buffalo smell the toxic chemicals and
avoid eating the plant.

Or, perhaps, the chemicals were designed to insects such as
grasshoppers that when
they traverse the plant some of those chemicals get on their bodies
and they irritate them.

I have never seen a grasshopper on the stems of any stinging nettle,
so I would bet it is
grasshoppers that are the main target of nettle.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies

A related point might be to ask where the nettle used to grow before
men started building latrines and spreading fertiliser everywhere!

S


a_plutonium wrote:
According to this website of a team of researchers:

Responses of Invertebrate Herbivores to Stinging Trichomes of Urtica
dioica and Laportea canadensis
Tracey D. Tuberville, Peter G. Dudley, A. Joseph Pollard
Oikos, Vol. 75, No. 1 (Feb., 1996), pp. 83-88
doi:10.2307/3546324
This article consists of 6 page(s).

They hypothesized that Urtica evolved more as a response to mammals
than to insects.

But I do not see how Urtica can penetrate the thick hides of most
grazing animals. I doubt that
stinging nettle would penetrate deer or buffalo.

As for mice and rodents, they would not do enough damage to the plant
to bother with.

So that leaves insects such as swarms of grasshoppers.

So I would have my bets not on mammals but insects and especially
grasshoppers.

Unless the stinging nettle works on the mouth and tongue of a mammal.
For humans it
would be the skin, since we are not eating nettle. So maybe it is the
mouth and tongue
of mammals that the nettle is targeting.

And then, of course, the evolution of the nettle was to ward off all
herbivores be they
mammals or insects.

Maybe the chemicals involved tell us who the targeted victims are?
Some say histamine
and acetocholine and folic acid are involved. So does anyone know if
these chemicals
target the mouth of a mammal or the mouth of a insect?

Perhaps the toxic chemicals involved tell us which mammals and insects
co-evolved with
stinging nettle.

Maybe the chemicals were not designed to penetrate grazing mammals but
were designed
for scent so that a deer or buffalo smell the toxic chemicals and
avoid eating the plant.

Or, perhaps, the chemicals were designed to insects such as
grasshoppers that when
they traverse the plant some of those chemicals get on their bodies
and they irritate them.

I have never seen a grasshopper on the stems of any stinging nettle,
so I would bet it is
grasshoppers that are the main target of nettle.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies

Archie, don't think hide, think mouth: The muzzle, lips, gums, and
tongues of grazing animals are just as affected by nettles as bare human
skin.

M. Reed

a_plutonium wrote:

But I do not see how Urtica can penetrate the thick hides of most
grazing animals. I doubt that

monique wrote:
Archie, don't think hide, think mouth: The muzzle, lips, gums, and
tongues of grazing animals are just as affected by nettles as bare human
skin.

M. Reed


Okay, and what would you say for grasshoppers and insects? Would it be
their mouthparts
and sense of smell and their "face area"? This should be easy enough
to research and find
a definitive answer as to how nettle evolved to ward off herbivores,
whether they be mammal
or insect.

The breaking off of the tip of the hyperdermic needle of nettles
suggests the intended victim
is when the mouthparts of the insect try to eat. And that it was not
intended to pierce human
skin but found it beneficial to the nettle. So I think the hyperdermic
needle geometry was
evolved for insects with the slightest touch would create the needle,
but that the needle
shape would also ward off humans.

I have never seen grasshoppers on nettle plants. I think grasshoppers
were the co-evolving
animal.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies

I ran a test on grasshoppers on stinging nettle. I rounded up some
grasshoppers to go jumping and flying into
a patch of stinging nettle. The end result was that they quickly
departed or remained "still" if they had landed on
a stem. Once they landed, they remained still until they either flew
away or dropped to the ground. None
moved up the stem. So apparently they were immediately affected upon
landing. Maybe it affects their
joints in their legs.

And of the 3 separate patches of stinging nettle, none had
grasshoppers of their own volition.

An interesting test would be to see if any caterpillers would remain
on the stems or leaves.

And would insects eat nettle if it were the only available plant?

I am not sure, but I think my donkey ate stinging nettle but he is
gone and cannot verify.
I suspect the horse and Llama eat stinging nettle when they are real
hungry and that
they will _not_ eat dock but will eat stinging-nettle. Again, that is
unverified.

I am going to test to see if goats eat stinging-nettle, which I would
guess they easily would.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies

On Tue, 07 Aug 2007 22:40:23 -0700, a_plutonium
wrote:

I ran a test on grasshoppers on stinging nettle. I rounded up some
grasshoppers to go jumping and flying into
a patch of stinging nettle. The end result was that they quickly
departed or remained "still" if they had landed on
a stem. Once they landed, they remained still until they either flew
away or dropped to the ground. None
moved up the stem. So apparently they were immediately affected upon
landing. Maybe it affects their
joints in their legs.

And of the 3 separate patches of stinging nettle, none had
grasshoppers of their own volition.

An interesting test would be to see if any caterpillers would remain
on the stems or leaves.

And would insects eat nettle if it were the only available plant?

I am not sure, but I think my donkey ate stinging nettle but he is
gone and cannot verify.
I suspect the horse and Llama eat stinging nettle when they are real
hungry and that
they will _not_ eat dock but will eat stinging-nettle. Again, that is
unverified.

I am going to test to see if goats eat stinging-nettle, which I would
guess they easily would.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies


Try frogs.

Nettles are the preferred food plant for some sorts of caterpillars,
including those of the Question Mark butterfly.

M. Reed

An interesting test would be to see if any caterpillers would remain
on the stems or leaves.

Archimedes Plutonium

And, you may find quite a few other plants feel stinging on the lips:
try Borage, and Green Alkanet, for example.

S


monique wrote:
Archie, don't think hide, think mouth: The muzzle, lips, gums, and
tongues of grazing animals are just as affected by nettles as bare human
skin.

M. Reed

a_plutonium wrote:

But I do not see how Urtica can penetrate the thick hides of most
grazing animals. I doubt that

In message , monique
writes
Nettles are the preferred food plant for some sorts of caterpillars,
including those of the Question Mark butterfly.

On this side of the pond the nettle is the food plant for the Peacock,
Red Admiral, Small Tortoiseshell and Comma, and a secondary food plant
for the Painted Lady.
--
Stewart Robert Hinsley