This is so rare I forget the common Chinese name and all searching has failed me. So you'll have to make do with the scientific names. I've never knowingly seen it fresh, but do occasionally see it dried.
In Latin, Desmodium intortum. In Chinese, 绿叶山蚂蝗 (Mand: lǜ yè shān mǎ huáng). I have never seen it fresh. In fact, I have only eaten it once at a buffet lunch in a local 5-star hotel restaurant. The Chinese government both owns the hotel and runs the star rating system, so take that rating with a pinch of salt.
In English, tick-trefoil among other names.
The dish I ate was Bullfrog with Tick-trefoil. Someone had scarfed half of it before I could take the picture. But I scarfed the rest. It was good with a capital GOO.