Old Plant in New Bloom

This plant is more than 35 years old. I found it 1983, left behind on a window sill.
It's a great survivor of many years of different homes and offices, and it has seen many different colleagues come and go, most of them refused forgot watering it in my holidays.
Sometimes it looks as if it's dying, two weeks later it's in bloom. I don't exactly know what it is, some kind of clover, I think. I've seen red variations, but never the green one I have. 
Just like books, I can't kick out plants.

19:25; 10°C