Though they're not sugary, the banner on this truck fairly labeled them "sweet." They continue to sweeten after they brown, and even shrivel, more than you'd probably tolerate in an apple eaten out of hand. Mind the little pits.
These (about $4 per pound), which had been grown in California, seem to be Indian jujubes, often called simply jujubes or, confusingly, Chinese dates. Their native habitat does include the southern Chinese province of Yunnan, as well as many other countries with warm climates, but another, hardier jujube species is widely grown in northern China.
Jujube truck
Middlesex St., Lowell, Massachusetts
(From an August 2009 visit)