The zinc content of plants on the friedensville zinc slime ponds in relation to biogeo-chemical prospecting

The zinc content of thirty different kinds of plants growing on slime ponds containing on the average 12.5 per cent zinc were determined by the dithizone method. The zinc content ranged from 39 p.p.m. in the fruit of the false Solomon's seal (Smilacina racemosa) to 5,400 in the horsetail (Equiseteum arvense). This latter plant varied considerably in zinc at different places on the slime ponds. The zinc contents of the aspen (Populus grandidentata), ragweed {Ambrosia artemisiifolia), and horsetail grown on normal soils are compared to those on the slime ponds and it is recommended that the poplar and ragweed be studied further as indicators of zinc ore bodies.