Two hypotheses were tested with respect to the germination of Diplolophium marthozianum, an endemic plant species of the copper-cobalt outcrops in Katanga, Democratic Republic of Congo: (1) germination of copper-endemics is limited by fungal infection in the absence of pathogen control and (2) the germination success of this copper-endemic species is copper-dependent. Seed lots of twenty seeds were weighed, soaked in different disinfection treatments and then placed in a germination medium containing four distinct copper concentrations for 30 days. Seed viability was measured at the beginning and at the end of the experiment by a cut test. Final germination percentage (15.2 +/- 8.2%) and seed viability (24.2 +/- 10.3%) were not affected by copper concentration or disinfection treatments. D. marthozianum is able to germinate in a substrate without added copper, despite pervasive fungal infection. However, seed mass had a significant positive effect on seed germination suggesting that selecting the largest seeds may ensure the highest germination success in ex situ conservation programs.