In my experience, (and we've grown a LOT of plants, from different sources) they are identical in all characteristics, other than color.
And, at that, many (tho not all) plants sport back and forth.

I would say there is no difference in their repeat.
They all crank up to re-bloom as soon as they're deadheaded. They all bloom through the calendar year for us, here near the Ventura Co. (CA) coast.

Jeri
(Who is leaving later today to travel slowly up to the Bay Area, for Celebration.)

Jeri, Do you think it possible that Larry Daniels might be the original OGR, and Grandmother's Hat the sport, which might tend to revert to the original?

Sure. That's possible. OR Tina Marie might be the original. The problem is, we are unlikely EVER to find proof, one way or another.

The rose grows at Sangerhausen.
But the labeling at Sangerhausen is problematical because with one problem and another, there's no clear line of identification. (Sangerhausen's loss of id on some roses is the source of some odd mistakes -- such as the confusion between 'Pink Gruss an Aachen' and 'Irene Watts.')

I think that, unless someone comes up with REALLY good evidence, they are going to just have the names they have, and as long as we all know what roses we're talking about I personally have no big problem with that.

"The roses know who they are . . ." Lee Jeremias said that, and it always made sense to me.

Jeri

The nurseryman who helped popularize Grandmother's Hat and isolated and named Larry Daniels and Tina Marie stated a full thirty percent of the plants he produced "reverted" to Larry Daniels. Sports occur serendipitously. Reversions, I've read, frequently occur about 30% of the time. Based upon that piece of information, I would think Larry is the original and the other two are sports. Whatever they are, they are great roses! Kim

But Kim -- How could he distinguish a sport from a reversion?

Jeri

Hi Jeri, that's actually easier than you think. When you have Grandmother's Hat in for propagation and three out of ten come out Larry Daniels, it would be considered a "reversion" as it is reverting back to its original form. It is virtually unheard of to have any rose "sport" from the original to a new combination at such a high rate. Mutations are known to revert to their original form that frequently, though. That's what convinced him Larry Daniels is, or is as close to what we're going to find, the original from which Grandmother's Hat sported. Kim