Plum

A plum or gage is a stone fruit tree in the genus Prunus, subgenus Prunus. The subgenus is distinguished from other subgenera (peaches, cherries, bird cherries, etc) in the shoots having a terminal bud and the side buds solitary (not clustered), the flowers being grouped 1-5 together on short stems, and the fruit having a groove running down one side, and a smooth stone. Generally, it has a purple colour, which is lighter on the inside.

Though originating on Earth, habitable planets colonized by the UNSC have been able to establish vast orchards of plums, especially Harvest before its destruction.