Prunus domestica

P. domestica is a very common cultivated plum tree in Colorado and around the world. It's in a lot of yards, and often escapes into wild, in this case meaning alleys, along streams and ditches and close-in open spaces.

It's probably a descendant of Prunus cerasifera, possibly hybridized with another plum in the genera. People have been eating the fruit for a long time. It was likely first cultivated in the Middle East. Stones from it's ancestors, thousands of years old, have been found in caves.

Archaeologists have found P. domestica seeds in the garbage dumps of Berenike, an ancient city in Egypt founded in the 200s BCE. Phoenicians were eating them in Sardinia at about the same time.

Roman soldiers apparently snacked on P. domestica prunes as they conquered the world. By the year 40 CE or so, they were dropping the seeds in Gaul and Britain. Yada yada yada... today the trees grow in Colorado.