I have a haunting memory of what I believe was the end of a movie broadcast in the United States (English language) on television from my early childhood. I don't think I could have seen it any later than about 1984 on TV, but the overall feel was very much the feel of a film from the mid to late 70s.
I didn't see much, but I took the plot to be that of a despairing escape from some sort of an unusual plant, that had the ability to freeze/immobilize/turn people to stone. My recollection of the last scene was that of a man fleeing to the outskirts of civilization in a 70's-esqe van, atop a barren hill. As I recall, the camera cut to inside the van, and the fleeing man turned toward the passenger side, only to find an unexpected plant.
I've been searching for this for years. I've spent a while looking through plot descriptions of horror movies from that era on Wikipedia, but haven't had much luck yet. I'm pretty sure it's not Day of the Triffids, although that comes up in my searches frequently (my reason being that I don't recall the plants being particularly mobile).
I would really love to find this. Hope you can help.