Copper tolerance of Viscaria alpina

Plants of Viscaria alpina (L.) G. Don. growing in an area of naturally copper rich soil and those in an adjacent normal soil were compared. The reasons for the copper tolerance of this species were sought at different biological organizational levels. The apices of many of the small lateral roots of the plants from the copper rich soil were either dead or abnormal. The root systems were much more irregularly branched than those of the control group. As a rule no continuous tap root was found on the plants from the copper rich soil. The capacity to form new adventitious, lateral roots as and when necessary is considered to be important for the survival of the latter plants. At the cellular level, in the cortical cells of the differentiating zone of the root apex, copper was stored both in the cell wall and in the cytoplasm; in the latter to a greater extent.