Plant roots contain a higher proportion of iron than the leaves and stems. The iron content of leaves is a function of the amount of chlorophyll present, which varies seasonally in any given species. The iron content of lichens and water plants, on a dry basis, averaged 5.16 and 4.99 milligrams per gram of dry matter, respectively; whereas the iron content of land plants on the same basis averaged only 0.30 milligrams. The relative absence of woody tissue in the lichens and water plants probably is the reason for the difference. Soil-rooted water plants are effective in removing iron from submerged soils, and the water-rooted types also seem to be effective in removing iron from the water. The .iron content of the soil-rooted type is about 3 to 7 times as great as that of the water-rooted type. The iron content for plants growing in rock, soil, and water environments agrees in general with published data.