Greenar is harvested by a Refinery. The Factory use it to produces Liftic.

A Greenar Mother attempts to spawn a crystal once every 8 seconds (240 frames) by default. At a fully upgraded portal it will attempt to spawn every 4 seconds. When it attempts to spawn it picks a random location around itself. If that spot is legal, it places the crystal. If not, it does nothing. It then repeats at the next interval. To be a legal location, the randomly chosen place has to be flat terrain, not contain something that occupies the terrain (like a unit), and not already contain a crystal. “Random” in this case means using a PRNG¹⁾ sequence that is seeded based on the location of the Greenar Mother