I've passed these tiny plants for a few years and finally took some off my stone wall outside. I see them growing around the neighborhood in the cracks of stone walls and edges where the ground meets the stone wall. They are not uncommon, but I've always wondered what they were since throughout the summer they are beautiful with lots of tiny pink flowers. I finally managed to keep one alive indoors, I damaged a few while transplanting. They're so tiny and fragile, what is it? Mini ivy? They love the shade. Well, I'm going to clip a few more from my walkway, because they are growing well indoors.