By using a dissection technique it was demonstrated that binding of Ni2+ ions occurred to both the algal zone and fungal medulla in various species of the lichen genus Umbilicaria. The algal zone, fungal medulla and lower surface plates in Umbilicaria muhlenbergii accumulated 21, 52 and 27% respectively of the total Ni2+ ions taken up. The amount of Ni taken up varied in different species of the same genus but in general the uptake by Peltigera (over 70 μmol g−1 dry weight) was some three times that by Umbilicaria under the same conditions.