This is a question for you plant experts out there.
I had a trivia question that has now turned into a curiousity I must
satiate.

There are plants that have both sexes and then other plants that only have
one sex or the other, right?

In regards to these single sex plants, the females reproduce by having the
pollen (sperm) brought to them by bees, wind, etc, right?

So, if I moved a female plant, for example, to an area of the country where
no plants of the opposite sex existed, the plant could not reproduce,
correct?

Can you name any specific examples?
Are there are any commonly known instances of this... where you have to have
an "opposite sexed" plant somewhere in your neighborhood or the plant won't
reproduce?
Or, is the requirement much more loose than that, and a potential "mate"
could be anywhere in the same state?

Thanks for your time.
Looking forward to hearing back.
cra2 "at" mindspring "dot" com

In article , cra2 deletethis_cra2
@mindspring.com writes

So, if I moved a female plant, for example, to an area of the country where
no plants of the opposite sex existed, the plant could not reproduce,
correct?

Yes, but. Many plants can also reproduce vegetatively.

Can you name any specific examples?

At one point it was believed that there were no locations in the UK
where both sexes of wild _Populus nigra_ existed sufficiently closely
together. (They've since found a reasonably sized population in the Vale
of Aylesbury.)
--
Stewart Robert Hinsley

Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

cra2 schreef
So, if I moved a female plant, for example, to an area of the country
where no plants of the opposite sex existed, the plant could not reproduce,
correct?

Can you name any specific examples? Are there are any commonly known
instances of this... where you have to have an "opposite sexed" plant
somewhere in your neighborhood or the plant won't reproduce?

In article , P van
Rijckevorsel writes
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

Apples for a start, though I wouldn't swear that it applies to all
cultivars. Sample URL -

http://www.ontarioprofessionals.com/trees.htm
--
Stewart Robert Hinsley

P van Rijckevorsel writes
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

Stewart Robert Hinsley schreef
Apples for a start, though I wouldn't swear that it applies to all
cultivars. Sample URL -

http://www.ontarioprofessionals.com/trees.htm
--
Stewart Robert Hinsley

+ + +
Afraid not. This is an example of a different mechanism, viz
self-incompatibility not based on mechanical principles. Self-incompatibilty
in apples is linked to genetic make-up, which means that an orchard composed
of a single clone (cultivar) won't produce fruit. For that a genetically
different apple is necessary (a different cultivar). Not all apple cultivars
are equally suitable as pollen producers.
PvR

That's not a case of unisexual flowers, though, not in the Rosaceae.
It's self-incompatibility. With things in this family (notably
cherries), often one cultivar is incompatible with itself and needs a
different cultivar. You can get around this sometimes by grafting on a
branch or two of a different cultivar.

M. Reed

Stewart Robert Hinsley wrote:

In article , P van
Rijckevorsel writes
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

Apples for a start, though I wouldn't swear that it applies to all
cultivars. Sample URL -

http://www.ontarioprofessionals.com/trees.htm
--
Stewart Robert Hinsley

Plants in many families can make fruit parthenocarpically (seedless fruit is
the result, so for a fruit grower that's still ok, but not reproduction). But
if not parthenocarpic, even fruits won't form.
Examples of dioecious plants that come to mind a

date palms (Phoenix dactylifera)
persimmon (Diospyros virginiana, D. kaki)
red maple (Acer rubrum)
Some hollies (not all) (Ilex spp.)
at least some of the ashes (Fraxinus spp)
papaya (Carica papaya), which has staminate, pistillate, and perfect-flowered
individuals
Some grapes, including the southern muscadine (Vitis rotundifolia), which, like
papaya, has all three types.
fig (Ficus carica), although females are often parthenocarpic, and of course,
the syconium is not really "fruit" tissue anyway, in the sense of being an
ovary.
Brazilian pepper (Schinus terebinthefolia)

In most of these examples, except for some horticultural cultivars selected for
their parthenocarpy, an isolated pistillate ("female") plant will not bear
fruit.

On 14 Jan 2003 00:14:41 GMT, (MMMavocado) wrote:

Plants in many families can make fruit parthenocarpically (seedless fruit is
the result, so for a fruit grower that's still ok, but not reproduction). But
if not parthenocarpic, even fruits won't form.
Examples of dioecious plants that come to mind a

date palms (Phoenix dactylifera)
persimmon (Diospyros virginiana, D. kaki)
red maple (Acer rubrum)
Some hollies (not all) (Ilex spp.)
at least some of the ashes (Fraxinus spp)
papaya (Carica papaya), which has staminate, pistillate, and perfect-flowered
individuals
Some grapes, including the southern muscadine (Vitis rotundifolia), which, like
papaya, has all three types.
fig (Ficus carica), although females are often parthenocarpic, and of course,
the syconium is not really "fruit" tissue anyway, in the sense of being an
ovary.
Brazilian pepper (Schinus terebinthefolia)

In most of these examples, except for some horticultural cultivars selected for
their parthenocarpy, an isolated pistillate ("female") plant will not bear
fruit.




Question: re. the Solo Papaya grown widely in Hawaii. I was told the
normal spawn was one third Female, two thirds bi-sexual. My guess was
that the males had a fatal gene and died. Is this correct?

I liked the fruit from the female trees better, but it was much less
available.


_

- Charles
-
-does not play well with others

On Mon, 13 Jan 2003 19:09:23 GMT, "P van Rijckevorsel"
wrote:

Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

cra2 schreef
So, if I moved a female plant, for example, to an area of the country
where no plants of the opposite sex existed, the plant could not reproduce,
correct?

Can you name any specific examples? Are there are any commonly known
instances of this... where you have to have an "opposite sexed" plant
somewhere in your neighborhood or the plant won't reproduce?




ginkgo

From: "cra2"

So, if I moved a female plant, for example, to an area of the country where
no plants of the opposite sex existed, the plant could not reproduce,
correct?

To pick a nit, the plant could not reproduce sexually. It could still propagate
asexually with cuttings, sprouts, rhizomes, divisions, or other methods of
spreading about.

Sean



--
Visit my photolog page; http://members.aol.com/grommit383/myhomepage
Last updated 08-04-02 with 15 pictures of the Aztec Ruins.
Address mungled. To email, please spite my face.

To start nitpicking: not all Rosacaeae are guaranteed to have perfect
flowers. It is the rule but exceptions can be found.
My local flora states that Sanguisorba can have 'male' flowers only
PvR

Monique Reed schreef
That's not a case of unisexual flowers, though, not in the Rosaceae.
It's self-incompatibility. With things in this family (notably
cherries), often one cultivar is incompatible with itself and needs a
different cultivar. You can get around this sometimes by grafting on a
branch or two of a different cultivar.

M. Reed

P van Rijckevorsel writes
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them
when feeling a little less woozy.
PvR

Stewart Robert Hinsley wrote:
Apples for a start, though I wouldn't swear that it applies to all
cultivars. Sample URL -

http://www.ontarioprofessionals.com/trees.htm
--
Stewart Robert Hinsley

Xref: 127.0.0.1 sci.bio.botany:18769

From: "cra2"
So, if I moved a female plant, for example, to an area of the country
where no plants of the opposite sex existed, the plant could not reproduce,
correct?

Sean Houtman schreef in berichtnieuws
To pick a nit, the plant could not reproduce sexually. It could still
propagate asexually with cuttings, sprouts, rhizomes, divisions, or other
methods of spreading about.

Sean

+ + +
To pick more nits: it is debatable if the option to be propagated still is
reproduction. IIRC there is a species of Cycad of which only a 'female'
specimen is known (perhaps it is in Kew?), so as a species it is just about
extinct.
PvR

"P van Rijckevorsel" wrote:
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

d buebly schreef
ginkgo

Actually this was just what I did think of but did not want to say.
Opinions vary if this is a useful 'fruit'. The Chinese like it, but in
Western cities there is a proscription to planting female trees because the
'fruits' have a reputation of smelling badly. I have heard of cases where
female trees were planted in busy streets but nobody noticed the 'fruits'.
Perhaps these only smell badly in (sub)tropical araes where they will rot
more easily?

Also Ginkgo's are gymnosperms and thus do not have true fruits! ;-)
PvR

I had assumed you ;-) would refer to the avocado, of which some plants are
female in the morning and male in the afternoon, while others are just the
reverse, with both groups needing to be present for fruit to set?
PvR


MMMavocado schreef
Plants in many families can make fruit parthenocarpically (seedless fruit
is the result, so for a fruit grower that's still ok, but not reproduction).
But if not parthenocarpic, even fruits won't form.
Examples of dioecious plants that come to mind a

date palms (Phoenix dactylifera)
persimmon (Diospyros virginiana, D. kaki)
red maple (Acer rubrum)
Some hollies (not all) (Ilex spp.)
at least some of the ashes (Fraxinus spp)
papaya (Carica papaya), which has staminate, pistillate, and
perfect-flowered individuals
Some grapes, including the southern muscadine (Vitis rotundifolia), which,
like papaya, has all three types.
fig (Ficus carica), although females are often parthenocarpic, and of
course, the syconium is not really "fruit" tissue anyway, in the sense of
being an ovary.
Brazilian pepper (Schinus terebinthefolia)

In most of these examples, except for some horticultural cultivars
selected for their parthenocarpy, an isolated pistillate ("female") plant
will not bear fruit.

I had assumed you ;-) would refer to the avocado, of which some plants are
female in the morning and male in the afternoon, while others are just the
reverse, with both groups needing to be present for fruit to set?
PvR BRBR

Yes, avocados are synchronously dichogamous (great dinner-party term to throw
around!), but they don't really fit into this discussion, since the flowers are
anatomically perfect. They simply mature their sexual whorls at different
times. Always female first, then male. Type "A" trees open female in the
morning, then close around noon, wait until the following day, and open after
noon functionally male. Type "B" trees open the first day in the afternoon, as
females, close for the night, and open the following morning functionally male,
then close by noon.

They do make mistakes, though. Some varieties can self-pollinate by not having
the stigma/style undergo senescence until well into the male stage. Others can
self-pollinate if the night-time temperature goes low enough to stop the female
flowers from closing.