It could well be a hybrid between the two. It will probably sucker as well, so I'd just leave it for another year or two. Inspect it, count petals, check fragrance, look at leaves and other similarities between its parents.
It seems you've ended up with an all new Gallica variety. You should be proud.

ITA with Ozrosarian.
You might want to count petals, anthers and stamens. Also photograph comparable leaves side by side on a scanner with a ruler. (some of this might point to chromasome doubling as a cause of the doubling of the petals.)

Do you know anyone at nearby rose societies who makes their own roses by cleft grafting or bud grafting onto multilflora? That would take minimal plant material, but would get you a duplicate, just in case.

Ann

I counted petals on two blooms of the sport/hybrid. They are 130 and 138. Some petals were small, from the center, and some were larger from the outside.

Then the odd thing is that I counted petals from r gallica officinalis bloom, to have a comparison of the natural parent. Taylor's Guide to Roses says r gallica officinalis has 12-18 petals while rosa mundi has 18-24.

The bloom I counted was dark purple and had yellow stamens. it was still fresh - many blooms on the r. gallica offic. bush are now spent - and it had 72 petals. Some were smaller near the center. Yesterday I looked with a friend and from eyeballing we did not see any blooms with only about 20 petals.

What do you think is going on?

Kathy

I would suggest that you post this thread on the Antique Roses forum here on GardenWeb. There are some folks on there who are quite familiar with the common variations in older roses and may be able to help you understand what you have - both with the seedling and with the parent plant.

Yesterday, I found one more bloom of the sport/hybrid. I tied a string to the cane, so I can find it later. I cut the bloom and photographed it on the stem and as a closeup front and side.

It was a 2 inch diameter and shaped like a zinnia pompom bloom. The leaflets are alternate. Leaf veins are mostly opposite, with some alternate. It is FRAGRANT!

Then I counted petals. This was a fresh, pink bloom, not dried up and brown like the last two. I counted 185 petals!!!

This is a more accurate count, as the previous counts were of dried up brown blooms that may have dropped some petals.

I also counted the "typical" r. gallica officinalis bloom. I got 75 petals for it, which is more than the 20 suggested by Taylor's Rose Guide.

Note this year's set of blooms are about 2 inches in diameter and they are smaller than two years ago in the photo (which are about 3.5 inches.) I shot photos this year and will try to post, but do not have electronic copies yet.

I will try to move this to Antique Rose Forum, but not sure how to do that. Kathy

Here is a link that might be useful:

The "typical" bloom that is dark pink/purple with yellow stamens and 75 petals is not typical. There were other blooms a couple weeks ago that probably had 25 petals; those were the typical rosa gallica offic.

Further, I will post 2010 photos of the 185-petal pom-pom sport/hybrid as soon as they are sent to me. Check the Antique Rose forum. Kathy