The igo plant grew on Terra Roxa. It started as coffee beans brought by human colonists. When the beans were planted in the Terra Roxan soil, they mutated. The beverage made from the igo plant was a hallucinogenic. It was banned and buried, and the natives switched to drinking tea.
Hundreds of years later, Bernice Summerfield visited Terra Roxa in the company of Sarger E!xhares, who was searching for the igo plant. When they found it, Sarger put some of the igo plant in his and Benny's food, causing them to suffer hallucinations. (PROSE: Solar Max and the Seven-Handed Snake-Mother)