strange behaviour in roses

Two different species of rosa were growing close to each other. They were seen to grow a single stem over a period of days. The stems from both plants entwined each other produced flowers. The flowers were next to each other and pollination occurred. One plant changed its external characteristics i.e leaf shape and colour.
I have not found any reference to this. What is this process called? I know its pollination that occurs, but what is the process in which the rose stems entwine and the whole rose takes on the characteristics of one species?
Many thanks if someone can answer this

Are you sure that you haven't had a sucker come up on at least one of the roses? Check if the branches come from above or below the graft (a knobbly section just above the ground). If they come from below they are suckers coming from the rootstock, which is different from the normal flowers. It will probably have leaflets which are a paler green than the rest, too.

If they are suckers they need to be removed by cutting off as close to where they emerge as possible. If you don't do this they will take over the rose and the graft will eventually die, leaving you with only the suckering shoots and their flowers.

Hi its definately not a sucker. One seems to be a wild species of rose which has come over from the neighbours garden and it joined up with our rose. The rose I have is not grafted as far as I know and the branch is high up on the rose so would be above the graft if there was one.

Not sure what's going on, then, but the fact that the roses entwined and flowered has nothing to do with the change in characteristics - pollination would only affect the seeds of the roses, not the roses themselves.

The likeliest thing is that the changed branch is a throwback to the rose that yours was bred from, so what has happened with it would be called regression.

Thanks I guess that's what has happened. It was strange the way the stems entwined then both produced flowers next to each other, which were in the exact position to touch and cross pollinate without any help. The whole rose not just the stem has regressed then, though it looks more like the neighbours wild rose.

Thanks for the help