That's totally cool! Carol

Here is a link to the study. Pages 35 and 36 discuss the roses that are all basically the same as Old Blush--including the Green Rose and Archduke Charles.

China Rose DNA study

What a charming little plant. If it doesn't have Old Blush's propensity to mildew, all the better.

I'm not so sure, Ingrid. When I click to get the full sized version of the whole shrub, I think I see mildew on the buds at the top left.

You're right, vmr. The Green Rose and Archduke Charles look quite different from Old Blush. Rouletii is very much smaller, but in these pictures at least, I can see it as being a drastically scaled down version of OB.

But Green Rose (unlike Archduke Charles) seems to be a sport from Old Blush.

See:
http://www.helpmefind.com/gardening/l.php?l=2.63942

According to the 2009 study both the GR and AC look like sports of OB.

That study has provided some significant insight and is often quoted. Amongst other interesting findings let me point out that SdLM is clustered firmly within the Tea rose group rather than the Bourbons and Miss Lowe's Variety is also clustered with the Teas rather than the Chinas. Mutabilis is plotted somewhere in between the Teas and the Chinas. That has confirmed suspicions that at least SdlM and Miss Lowe's Variety (hence Sanguinea also?) should be considered Teas albeit somewhat atypical in their respective bloom forms in that the one has an OGR-like bloom form and the other is a single.

Rouletii looks like a scaled-down version of Old Blush. I never thought about the fact that they are genetically identical. There is a Rouletii impostor in my area that makes the rounds at rose shows. It has more petals and the bush is much more dense than Rouletii ... a lot like 'Trinket' or 'Pink Ribbon'. Saw it once on the head table as best OGR. (I kept my mouth shut.) I grew this impostor for a while. It was given to me as a tiny rooted cutting, and I had no reason to doubt it till it gained some maturity and showed that it wasn't who it was supposed to be. Now, it's happily living in another friend's garden as "Not-Rouletii".

According to the article, the following roses were determined to be sports of Old Blush, and genetically identical:

Climbing Old Blush, Green Rose, Single Pink, Rouletii, Pompon de Paris, Bengale d'Automne, Archduke Charles.

The study said it had been speculated that Archduke Charles was a seedling of Old Blush, but the specimen from ARE tested as indentical.

And there were several roses usually listed in catalogs as Chinas that fell closer to the Tea group: Spice, Ducher, Jean Bach Sisley, and as Nik said, Miss Lowe's Variety.

But I think what vmr is saying, is similar to the idea that Vintage had of grouping roses according to growth habit because that is more useful for gardening purposes. And it makes sense to know that something will grow more like a China than a Tea even if it's really a Tea.