DUE TO INVESTIGATING THE EFFECT OF DROUGHT stress ON THYMUS SPECIES, A FACTORIAL DISIGN UNDER COMPLETELY RANDOMIZED DESIGN CONDUCTED WITH FOUR REPLICATIONS. THE FACTORS OF GERMINATION IN VITRO INCLUDED THYMUS SPECIES (T. ERICALYX, T. KOTSCHYANUS, T. VULGARIS) AND SECOND FACTOR WERE INCLUDED DROUGHT stress BY PEG IN 5 LEVELS (-3, -6, -9, -12 BAR AND WELL WATER (CONTROL)).