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Nomenclature and crosses

Posted by leftwood 4a MN (My Page) on
Sat, Nov 18, 06 at 14:22

Precursor: Depending on which is the seed parent or pollen parent, sometimes crossing species can produce two quite different groups of seedlings.

Question: Would these two seedling groups be given different grex epithets?

(Not sure if I am using the term "grex" correctly: in Acer x freemanii, freemanii is what I call the grex name. Some explanation of this concept would be greatly appreciated also.)

Rick


Follow-Up Postings:

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RE: Nomenclature and crosses

I thought it interesting that OneLook Dictionary gives the GardenWeb Glossary of Botanical Terms as the only botanical definition for grex. This says

"grex
A group name for all plants derived from crossing the same two or more parent species; the herd or hybrid swarm."

according to OneLook.


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RE: Nomenclature and crosses

I would say NO to your question at this point. But, my experience is merely based on my laymen discussions and literature reviews on one palm cross (the Mule Palm) that will result in different phenotypes depending on which palm is used for hte pollen and which for the egg, etc.

X Butiagrus nabonnandii is the mule palm, and parentage of Butia capitata with Syagrus romanzioffiana. I have never seen printed differentation in the botanical name regarding the separate phenotypes of the mule palm that occur when the sex gametes of the parents is switched.


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RE: Nomenclature and crosses

Acer x freemanii is not a grex name, it is a nothospecies name.

Grex names are essentially limited to a few heavily-cultivated groups that hybridize readily, for the most part only the orchids and bromeliads, and are not part of formal systematic botany under the ICBN (International Code of Systematic Botany). They are written like this: "Phragmipedium Abracadabra" and are distinguished from systematic names in format by the lack of italicization/underlining of, and capitalization of the first letter of the grex name (in this case "Abracadabra").

Nothospecies names are simply the names of any hybrids at the species level that are named under the ICBN. Like all specific epithets, they are lowercase & italicized or underlined; to indicate that they are hybrids, they are preceded by an "x". Within the ICBN, nothospecies names are independent of the direction of the cross (see here).

Patrick Alexander


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RE: Nomenclature and crosses

Thanks Patrick! So often I just get little bits and peices of an answer. It's really refreshing to get a "complete" reply (although I do see there is so much more). I'm just soaking it all up.

And shame on me for not italicizing (or underlining), especially when the basis for the question screams for it!

Rick


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RE: Nomenclature and crosses

Hi Rick,

Great topic. Thank you for posting this interesting question.

I'll offer you my take, which is considerably lighter in tone. Do you remember the old TV beer commercials about Miller Lite, Less Filling versus Tastes Great. This is similar to the world of plant classification. Imagine a bunch of plant people at a bar, one side is the ICBN (International Code of Systematic Botany) and the other side is the ICNCP (Internation Code of Nomemclature for Cultivated Plants). The only time that these people talk to each other is after consuming a considerable amount of beer and with much yelling and finger pointing. The only thing that they agree on is to disagree.

The ICBN looks at nature (essentially the evolution plants) and the ICNCP looks at human cultivation of plants. The fact that the two groups might be talking about the same plant never is acknowledged. It's just too much fun drinking beer, yelling, and pointing fingers.

I'll attempt to take the middle ground and say that both groups are correct and offer some comprimise. Of course, now both groups will start yelling and pointing fingers at me. Alas, so be it.

Let's assume that in a well documented observation we find that a Pelican is blown 1000 miles inland by a hurricane. Suppose that Pelicans are not normally observed this far inland. Furthermore, assume that the bird is covered with pollen and it lands, exhausted, in a field of flowers. As it happens, the pollen of a distant species fertilizes the local endemic plant. Since the Pelican is natural and the hurricane is natural, then the plant cross must be a naturally occuring hybrid. Let's call it by my made up name, Flowerium x pelicana. Clearly this is a plant claimed by the ICBN.

On the other side, a gardener grows this distant species in a pot on their windowsill and the endemic species grows natively in their backyard. The gardener crosses the two plants with an artists paintbrush and produces a manmade cross. In all ways the manmade cross appears identical to the naturally occuring hybrid. What to do? How is this plant to be identified?

The grower consults the ICBN and is booed and hissed out of that section of the bar. A human is clearly not considered part of nature. How could anyone confuse a human intervention with a Pelican being blown inland by a hurricane. Clearly one is natural and one is not.

The grower goes to the other section of the bar and is embraced by the ICNCP. After many beers, the ICNCP suggests a name. Let's call the plant, Flowerium Pelicana.

So, I offer you this. Call the naturally occuring hybrid by the nothospecies, x pelicana, and call the cultivated plant by the grex, Pelicana.

Outraged, both the ICBN and ICNCP threw me out of the bar. Blasphemy!, they yelled at me with fingers pointed. So, I, the gardener, and the Pelican, went home with a six pack and decided to sit around and just admire the plant. The flowers sure are pretty, no matter what the name happens to be.

Tom


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RE: Nomenclature and crosses

  • Posted by josh z8a (My Page) on
    Sat, Dec 23, 06 at 11:54

Thanks, Patrick and Tom (You deserved your beer...very witty!)for very helpful answers. Great topic and I think I understand now. josh


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RE: Nomenclature and crosses

And the clear water becomes even more clear. Thank you too, Tom. Your analagy is quite clever, and I would venture, makes botany fun, even for the uninterested.


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RE: Nomenclature and crosses

This reminds me of a conversation which I swear is true.
"You cannot be a scientist. You are too romantic."
"In order to be a scientist you've got to be romantic"


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RE: Nomenclature and crosses

Does that mean that no manmade hybrid can have a nothospecies name? And what about interspecific crosses, like xChitalpa tashkentensis?


 
 

 

 


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