Plant 42 was a large plant infused with the t-Virus, and was originally part of an experiment on botanic subjects by Umbrella researcher Dr. Henry Sarton. The name location that the plant was growing on was "Point 42" of the dormitory (Plant 42 would literally mean "Plant at Point 42").
Plant 42 was created by Henry Sarton, who injected a plant living in Point 42 with the t-Virus out of curiosity. Plant 42 proved to be completely unique, incomparable to any other plant-based test subjects. Its roots buried deep through the wood and concrete in the residence and began feeding on the chemical-rich water of the Aqua Ring, likely promoting further growth. Expanding its vines across the building, it used cracks in the flooring to attack passing staff members, feeding on their blood.[excerpt 1]
By May 21, Plant 42 had completely taken over a room of the dormitory. Able to manipulate doorknobs and move its vines, Plant 42 captured and drained several researchers of their blood when they tried to destroy it. It was discovered by Sarton's team that Plant 42 was sensitive to a chemical known as UMB № 20, otherwise known as V-JOLT. A plan was devised to destroy it, involving feeding it directly to the roots. However, this plan could not be accomplished, either due to the continued deterioration of the researchers' health from t-Virus infection or because of the escaped Neptunes in the flooded Aqua Tank chamber. Plant 42 was finally destroyed on the night of July 24 when S.T.A.R.S. searched the dormitory building.
As a result of the research staff's continued work during the outbreak, Umbrella was able to receive research data on the Plant, based on the 'Plant 42 Report'. The company soon after developed the smaller, more mobile "Plant 43", which was in development in Raccoon City prior to its own viral outbreak.