A cotton harvester includes plant cutting apparatus to sever cotton plants from a ground surface, plant conveyor apparatus to convey the severed plants into and through a picking chamber, and cotton picking apparatus including picker spindles that move upwardly into the picking chamber through a floor of the chamber to pick cotton filaments from bolls of the plants conveyed as a flattened mat therethrough and carry the cotton downwardly through the floor to doffers that remove the cotton from the spindles. Cotton conveyor apparatus also below the floor conveys the cotton to a receiver, while the plant residue passes from the chamber.