It is not fully known what function the plants' thorns serve. The plant may be another form of carnivorous life, feeding on animal lifeforms that succumb to its thorns, or it may be a form of defense mechanism for the planet itself, under control of the ruling computer Vaal. In 2267, a landing party from the USS Enterprise lost crewmember Hendorff to a pod plant, and nearly lost Spock as well. Fortunately, Spock responded well to a dose of masiform-D from Dr. McCoy, and made a full recovery. (TOS: "The Apple" )