The Apple

Gamma Trianguli VI is a peaceful planet with abundant plant life. It seems a paradise, but the landing party soon feels the thorns: poisonous plants, killer storms, and explosive rocks all claim lives. Eventually, they discover a small community of primitive people who serve the mysterious Vaal, an immense statue, chiefly by feeding it when it demands this. These people live immensely long lives, and do not age or procreate unless there is an accident. Theirs is a stagnant society, and into the bargain Vaal apparently has the means to attack the Enterprise...