There are two types - Chinese and Indian
Chinese will be smooth and light green in color and the other is the one you are asking.
It is called Cundiamor indu.
You know it is bitter and never seen in shops. But if you pass by La vega you can take the Sabaneta Road and ask in one of the exporting companies to give you some.
If you are in Santo DOmingo, I heard they sell in Chinatown.