From Halopedia, the Halo wiki
The Ugparassa tree is a type of plant which was present on Forerunner worlds. Such trees existed inside the shield world Requiem, for example at the makeshift facility Galileo Base. Consequently they also appeared in the simulated environment "Complex" used by the Spartan-IVs for War Games training aboard UNSC Infinity. Ugparassa trees were used by the company Have S'Moa to smoke the bacon used on some of their hamburgers.
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