The plants of PJ2-445 are interconnected by an elaborate underground root system and are able to grow rapidly from the ground to nearly six feet in height, then quickly retract again. They naturally emit a low pitched inaudible sound which the humanoid alien beings of the planet require to live, and in turn the plants respond to the unique trilling song produced by the humanoid beings. When injured by the UAV, the plants produced a sound of altered pitch which caused physical side effects in SG-1 including headaches, nausea, and severe irritability, and resulted in serious illness among the native beings until the tone was corrected.
Cross Reference: PJ2-445, PJ2-445 Humanoids
Episode Reference: One False Step