* Author for correspondence and reprint requests Z. Naturforsch. 54c, 698-703 (1999); received November 17, 1998/March 20. 1999 a-Tocopherol, Photosynthesis, Drought, Rosmarinus officinalis, Melissa officinalis Summer diurnal variations of photosynthesis and a-tocopherol content were measured in relation to natural drought in field-grown rosemary (Rosmarinus officinalis L.) and lemon balm (Meli...