mysterious green middle eastern plums I was on a trip to the middle east a year or so ago around mid spring.  I was offered what looked like a green plum. 

The taste was very sour and hard (not soft like a plum). The locals called it "janarek" and for the life of me I can't find it here in North America.

The closest I've found were the yellow and golden plums

the mysterious green plums I'm talking about are a bit smaller and lot crunchier. 

any ideas on what its name, and where I can buy it from?
Maybe you had the Greengage plum.