The obvious advantage is protection of getting chewed by vegeterians (deer,
horses, sloths and all those big megafauna they evolved along with).
The second, if I remember correctly, the thorn is moisture control for the
plant. Kind of a plug in the pore that swells it shut in the heat of the day,
but lets the plant respirate in the evening when temperatures are more
condusive to only letting off a little bit of your water.
-----Original Message-----
From: John Bongiovanni
Sent: Friday, August 30, 2002 2:39 PM
To: nanfa_at_aquaria.net
Subject: Re: NANFA-- OFF TOPIC - Speaking of symbiotic relationships RE;
Moth pollinators
While we have diverged onto plants... I was wondering what the evolutionalry
advantge would be to thorns other than snagging the seine as I pass by? South
Texas is overrun by thorny bushes, trees, grasses. Everything has a thorn it
seems. Its also interesting that the thorns are forthe most part restricted
to semiarid biomes. Farther North of course blackberry bushes and the like,
are present but thorny plants are not as prevelent.
John
>
> From: HOLLIS1506_at_webtv.net (Leo Arieux)
> Date: 2002/08/30 Fri AM 10:26:45 CDT
> To: nanfa_at_aquaria.net
> Subject: NANFA-- OFF TOPIC - Speaking of symbiotic relationships RE; Moth
> pollinators
>
> There is a group of monopodial orchids largely restricted to Africa and
> the Islands of the Indian Ocean.The specific genus and species is
> Angraecum sesquipedale. It is known as the Star of Bethlehem Orchid
> which has star shaped ivory/white flowers that bloom around Christmas.
> Two to four waxy flowers up to 7 " across seem to glow against a
> background of dark green strap like leaves. There is a barely noticeable
> nectar tube which is a whitish green spur, almost 12" long.
>
> Now to the point.....over 100 years ago, Charles Darwin was studying the
> fertilization of orchids by insects. He predicted that in Madagascar,
> there must be a moth with a 10 to 12" probiscus capable of reaching to
> the bottom of the spur/tube and fertilizing this flower. Many years
> later such a moth----- the night flying Xanthopan morgani praedicta
> ----
> was discovered.
>
> There is another orchid, which I am familiar with that _only_ has
> fragrance at night and is visited by moths, Brassavola nodosa, the Lady
> of the Night Orchid which has slender green- gray "rat tail" type leaves
> with small white delightfully
> fragrant flowers. I have seen moths pollinating the flowers at night on
> my patio, a very interesting phenomena.
>
> On a side note there is another species of terrestrial orchids (Ophrys)
> with approximately 30 species. Ophrys insectifera, has a lip that
> resembles the female Argogorytes mystaceus wasp. A male wasp in
> attempting copulation fertilizes the flower. The inter relationship
> between animals and flowers never fail to amaze me. It is a shame that
> man doesn't respect the natural world and it's beauty more.
>
> Leo
>
> ************************************
> Laissez Les Bon Temps Rouler'
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/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
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/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
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/-----------------------------------------------------------------------------
/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org