A greel tree was a type of tree native to Pii III and Pii IV, the only planets with the proper ecosystem to support the fastidious trees. The Greel Wood Logging Corporation, based in the Pii system, maintained a monopoly on harvesting them. The crimson timber—greel wood—was in great demand as a luxury item. Industrial Automaton designed a logging droid to specifications for the Greel Wood Logging Corporation, which used them on the rolling hillsides of Pii III. They were apparently very expensive.
- "The Greel Wood Haven"—Star Wars Adventure Journal 6
- Gundark's Fantastic Technology: Personal Gear
- Geonosis and the Outer Rim Worlds
- The Essential Atlas