Well I'm still confused by your terminology. I took the following definition
of hybrid from a biology link:
hybrid
(Science: biology) An offspring of parents from different species or
sub-species.

An organism that is the offspring of genetically dissimilar parents or
stock; especially offspring produced by breeding plants or animals of
different varieties or breeds or species; "a mule is a cross between a horse
and a donkey".

Produced by crossbreeding.

Commercial varieties of walnuts are not hybrids, since they all come from
the same species. They are cultivars, or varieties - meaning, that some
chance-mutation with a better taste, longer shelf-life, or some other
distinguishing feature, showed up on a tree somewhere and was subsequently
propagated by grafting or some other technique. In some few cases, there
might be hybrids between sub-species - but I'm not sure that the Carpathian
walnuts are sufficiently different genetically from the persion walnuts to
merit sub-species title. If they were, some different cultivar might
originate by crossing by hand pollination Carpathian with Persian walnuts.
However, I doubt that has happened. Some species, like the walnut, have wide
climate adaptability, and over thousands of years, the best-adapted plants
have been more successful in surviving in any given climate. Therefore, it
makes sense that walnut trees and their seedlings that have survived for
2000 years in northern Europe would have more tolerance for cold than walnut
seedlings from trees in Iran. I'm really just nit-picking, because, for
practical purposes, people in the Northern half of the US must use
descendants of Carpathian walnuts if they want to get nuts, which I think we
both agree on.


"Stephen Henning" wrote in message
news
"presley" wrote:

Well there are some inaccuracies in your statements. Carpathian walnuts
are
the same species as English walnuts, just a hardier variety of the same
species found growing in Eastern Europe. Black Walnuts are great for
eating
and rich in oils - but have a very hard shell and outer hull - some
people
have found they do best by driving their cars over the outer hulls to
separate out the walnuts.

Most commercial walnuts are not species but hybrids. In California they
use 30 different hybrids of English Walnut (Juglan regina). In addition
to these commercial varieties, there are also different strains of
Juglan regina including the German, Italian or Carpathian which are
hardier and do well in colder climates. The original (English)
variation of the species planted in England came from Persia or Iran and
is much more tender. Hardier strains were collected from high in the
Carpathian Mountains, which extend from Slovakia and southern Poland
southeast through the Western Ukraine to northeast Romania.

The Persian/English strains will grow in the northeastern US where I
live but nut production is very poor or non existent. Harsh winters
leave a lot of dead branches. However, the Carpathian strains will do
quite well. They are usually grafted on English walnut or black walnut
rootstocks.

For a nice read on this visit:

http://www.songonline.ca/nuts/persian_walnut.htm

A parallel situation exists with Douglas Fir (Pseudotsuga menziesii)
Christmas trees which are grown from seed collected in many different
states at many different elevations from Canada to Texas and from sea
level to over 6,000 ft. They are all the same species, but they are
quite different. By knowing latitude and altitude of where the seed was
collected, you can predict where it will do well.

The taxonomic handling of such variation is often handled by forming
subspecies or groups. The difference is not enough to form different
species, but quite significant when looking for source material for
different areas.

--
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Cheers, Steve Henning in Reading, PA USA
http://home.earthlink.net/~rhodyman