I had to cut down a branch of a climbing rose, which has a lot of unripe hips. I cut open a couple of the hips, and the seeds seem reasonably well formed. Is there any chance these seed are mature enough to germinate?
It’s always worth trying. Nature provides many possibilities. Don’t you think it possible some MAY germinate, even if WE don’t think they’re ripe? She provides for many potential issues. Perhaps not being sufficiently ripe may be one? Perhaps some will in case the season is short due to odd weather conditions? Everything is designed to perpetuate the species before it dies. I have to think “Nature” has prepared for virtually any potential issue. I say, IF you have the room, time and energy, plant them and see. Otherwise you may never know and may be tossing seeds which might hold results you want. Fingers crossed for you!
The achenes are still looking fresh. From my experience I can say, that if a finger pressure on the seed gives way, the germination will not succeed because the achene is still too soft and the development will be not far enough advanced. You would not find them again after stratification, they dissolve completely similar to the infected ones. For the harder ones, I agree with @roseseek, it’s definitely worth a try. Good luck!
I’ve had success with hips that look like your picture.
If i am correct I had a big hip on Ashram last year and seeds germinated. It was on the bush for a long time but it did not turn color. I have a few hips this year I am going to test.