I have seen this fruit occasionally on sale at our fruit stalls in Singapore, and I always thought it was just a different kind of rambutan. I love rambutans but I’m put off by the seed-coat that often sticks to the flesh. Hence I seldom eat the fruit except in the canned version. When I asked the fruit seller if they were rambutans, he corrected me. This fruit is called Pulasan and it has absolutely no connection with rambutan.
According to Wikipedia, Pulasan means “twist” in Malay, because the way to remove the skin of the fruit is to twist it off. This fruit tree thrives in very humid regions, and the fruit looks very much like rambutans, except the spines are not hair-like but short and blunt.
Even the flesh looks like that of the rambutan. However, it is much sweeter and juicier and the flesh separates from the seed-coat easily. The ovoid seed can be eaten raw and it tastes like raw almond.
Pulasan can found in Malaysia, Thailand and the Philippines. In Chinese it is called 葡萄桑.