[pbs] pollination
German Roitman
ggroiti at mail.agro.uba.ar
Mon May 31 22:29:13 EDT 2004
Hi Judy:
As i have worked in pollination some years ago i can add some things.
At 09:50 31/05/2004, you wrote:
>A couple of times now I've heard this fabulous lecture on pollination
>biology by Larry Mellichamp who teaches at UNC in Charlotte, North Carolina
>and hybridizes sarracenia for fun.
>
>Bat pollinated plants are night blooming, often white flowered (though
>that's often more applicable to moths) and, more importantly, tall - think
>yuccas - so bats have an easy time getting at the flowers. Close to the
>ground would be a problem.
Not always white, some times are dark red, like in Kigelia, the sausage
tree, the long inflorences almost reach the ground, but smell (usually
fruit like) is very important. As far as i know Yucca is pollinated by the
yucca moth, a small moth that pollinate and lay the eggs in the ovary so
the larva can eat the fruit without damaging the seeds.
During the nights bats and moths are the most common pollinators but also
small mammals (rodents and marsupials) also visit the flowers. Recently a
few species of nocturnal bees has been reported visiting orchid flowers in
Ecuador.
>Lots of flowers have yellow markings, called bee guides, to show insects the
>way to pollen and nectar. Think of iris, where German iris have fuzzy
>markings and I. versicolor has coloration at the base of the falls. We
>humans see a portion of the spectrum egocentrically called "visible light."
>Insects see further into the ultra violet. Using a black light will make any
>such "hidden" markings visible to us.
That´s true, sometimes nectar guides are just that, and there are no reward
inside, it use to happen in some orchids, like Bletilla were there is no
reward but very big nectar guides in the labellum.
>Scent is a whole other technique - carrion/ rotting meat often coupled with
>dark red flowers (Asarum canadense) attracts carrion beetles or flies, sweet
>fragrances butterflies and bees.
There is amazing information about the power of scent to attract
pollinators, and sometimes scent is a reward itself, some males of bees use
the scent of certain orchids to enhance the power of there own smell and be
more attractive to female bees. In this case the one that use is the male
not the female.
>Some flowers are bird-pollinated - and not just humming birds. I came across
>a report that blue tits in England would enter the flowers of Fritillaria
>imperialis.
Hummingbirds-plants is considered the largest and highly specialized
assemblage of flower-feeding birds, but many other birds can visit and
sometimes pollinate flowers. In South America at least three or four cases
of a very particular bird-flower interaction has been recently
reconsidered. I have studied the bird pollination of Myrrhinium a small
tree of the mirtaceae. The flowers produce fleshy petals and is visited by
Thrushes and mocking birds among others, they eat the petals like fruits
and pollinate in that way.
>It's a fascinating topic.
I completely agree with you
Best wishes
Germán
_________________________________________
Ing. Agr. MSc. Germán Roitman
mailto:roitman at mail.agro.uba.ar
Cátedra de Jardinería
Coordinador de la Carrera Técnica de Jardinería
Facultad de Agronomia.
Universidad de Buenos Aires
_________________________________________
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