Subject: Re: Ginko biloba

From: [email-masked] (Una Smith)
Date: 14 Jun 1995 18:04:33 GMT

Harvey Rutt <[email-masked]> wrote:

>I believe [Ginkgo] was only known from the fossil record until China &
>Japan opened up to the West.

Ginkgo biloba is thought to have survived in the wild in China until a
few thousands or perhaps hundreds of years ago.  It survives today only
in cultivation, except for a stand in China (but there is some question
about whether it was planted by humans).  I have seen fossil Ginkgo in
the Cretaceous (>65 million years ago) of North America, and I think it
was once extremely widespread and common.  For more details, see these
textbooks (both in print):

Stewart, W.N and G.W. Rothwell (1993) Paleobotany and the evolution of plants.
        2nd edition.  Cambridge University Press, Cambridge.  Loaded with
        pictures and exemplary discussion of the relationships between taxa.

Taylor, T.N. and E.L. (1993) The biology and evolution of fossil plants.
        Prentice-Hall, Englewood Cliffs, NJ.  ISBN 0-13-651589-4.  Hbk.
        More comprehensive and detailed than Stewart and Rothwell (1993),
        but with somewhat less synthesis.

>'Ginko nuts' are used in oriental cooking, but I do not know if they
>are *really* from the ginko tree.

They are.  They are the seed sans pulpy rind.  The rind smells foul and
can cause severe irritation on contact.

>Why are most plants hermaphrodite ...

Perhaps for historical reasons:  the ancestors of the most successful
plants just happened to have perfect flowers (both sexes together in
a single floral organ).

Perhaps for adaptive reasons:  the literature on breeding systems and
the causes and consequences of various modes of sexual reproduction 
is huge and complex.  Would anyone else reading this care to offer a
thumbnail sketch?

---

From: [email-masked] (Harvey Rutt)
Date: 14 Jun 1995 15:40:11 +0100

In <[email-masked]> [email-masked] (Rusty Osborne) writes:

>>  What is the term given to plants which have male and female 
>> counterparts, thus allowing for only cross-fertilization? Am I correct in 
>> thinking this term is "dioecious"? I think the ginkgo plant is just such 
>> a plant, do any of you know any info about this plant?
>> 
>>  

>You are correct, sir! "Dioecious" is a greek construction meaning "two
>households", i.e., male/female, +/-, yin/yang. A species having staminate

We have several very attractive ginkos on campus. Very unusual fan
shaped leaf, nice conical shaped tree.
I believe it was only known from the fossil record until China & Japan
opened up to the West.
'Ginko nuts' are used in oriental cooking, but I do not know if they
are *really* from the ginko tree.

Returning to the original qn.
Why are most plants hermaphrodite (can the term be used for plants -
its dictonary definition appears to permit it) when most higher
animals are dioecious (reverse qn; can the term be applied to
animals...)

Harvey Rutt
no botanist - brief chance visitor here! But I like ginkos....

ps the gingko is also spelt ginkgo and ginko and is known as the 'maidenhair
tree' in the UK; anyone know why?

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From: [email-masked] (JRR)
Date: Wed, 14 Jun 1995 17:44:33

In article <[email-masked]> [email-masked] (Harvey Rutt) writes:
>From: [email-masked] (Harvey Rutt)
>Subject: Re: ginko biloba
>Date: 14 Jun 1995 15:40:11 +0100

Ginko nuts' are used in oriental cooking, but I do not know if they
>are *really* from the ginko tree.

Yes, they are from the ginkgo tree, although I believe a curing process is 
used to make them edible!

John

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From: [email-masked] (Joseph Joaquin Amaya)
Date: 12 Jun 1995 16:20:38 -0400

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From: [email-masked] (Jason A Broder)
Date: 14 Jun 1995 03:44:16 GMT

Joseph Joaquin Amaya ([email-masked]) wrote:
:  What is the term given to plants which have male and female 
: counterparts, thus allowing for only cross-fertilization? Am I correct in 
: thinking this term is "dioecious"? I think the ginkgo plant is just such 
: a plant, do any of you know any info about this plant?

:  
   hello hello

  The word dioecious is derived from greek meaning 'two houses'. You are 
correct in your assumption. Another example of a dioecious plant is 
Cannabis sativa.
  The ginko tree (Ginko biloba) is also known as the maidenhair tree. It 
received it's english name from the resemblance of its leves and leaflets 
to those of maidenhair fern.
  It grows slowly, reaching hieghts of up to 30m+. Ginko is deciduous, 
this is unlike most other gymnosperms. It is the last surviving species 
of the division Ginkgophyta. There probably no stands of wild Ginko left 
anywhere in the world, however the tree was preserved in temple grounds 
in China and Japan. It has been introduced to other parts of the world 
and has been included in parks and gardens in temperate areas for about 
200 years! Its resistance to air pollution make it a good choice for 
urban parks. Ginko is dioecious.

						Enjoy yourself,
							Jay
        ************************************************************
        **    \ (` /                                              **
        **     \`)/      BOOOOOOOOM                               **          
        **     ----                 SHIVA!!!!                     **           
        **     \  /                                               ** 
        **      \/                            [email-masked] **               
        ************************************************************

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From: [email-masked] (Rusty Osborne)
Date: 13 Jun 1995 14:39:54 GMT

In article <[email-masked]>, [email-masked]

You are correct, sir! "Dioecious" is a greek construction meaning "two
households", i.e., male/female, +/-, yin/yang. A species having staminate
and pistillate flowers borne on separate individuals. Ginkos are ancient
deciduous gymnosperms, I think endemic to China, and are favored as urban
landscape trees due to an apparent resistance to air pollution. The female
tree is very messy so males are preferred. 
-- 
"If I knowed I coulda rode I woulda went."
- Mortimur Snurr

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From: [email-masked] (Una Smith)
Date: 13 Jun 1995 14:36:58 GMT

[email-masked] (Joseph Joaquin Amaya) writes:

>counterparts, thus allowing for only cross-fertilization?
>Am I correct in thinking this term is "dioecious"?

Obligate cross-fertilization is achieved through several
mechanisms, including dioecy. 

Dioecious plants have obligate cross-fertilization, because
each plant produces only male flowers or only female flowers,
instead of both (monoecy) or perfect flowers (with both male
and female function).

>I think the ginkgo plant is just such a plant, do any of you
>know any info about this plant?

Yes, Ginkgo trees are dioecious.  See Foster and Gifford's
"Comparative Morphology of Vascular Plants" for more about
this.

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From: [email-masked] (Jim Brewster)
Date: 14 Jun 1995 16:42:37 GMT

In article <[email-masked]>, [email-masked] (Harvey

> animals are dioecious (reverse qn; can the term be applied to

"Why" is a pretty ambiguous question in evolutionary science, and one that
implies purpose or intention. Perhaps it would be better phrased as: "How
did it come to be that ...?" And even that question is pretty perilous.
Perhaps the best answer is "Because they are." 

Anyway, it may have something to do with the differences in mobility and
dispersal between animals and plants. Or perhaps the complex mating
behaviors of higher animals make it difficult to be both male and female at
the same time, although there is a fish that can switch from functional
female to functional male during the course of its adult lifespan.