 However, the tree had only been screened for non-aggressive or semi-aggressive isolates of the causal fungus of Dutch elm disease.When its low resistance to the new strain of the disease became apparent, sales plummeted, and only 500 were sold in 1990.However, neither 'Commelin' nor its slightly less vulnerable contemporary 'Groeneveld' had sold in great numbers beyond the Netherlands, although it was later used in hybridization experiments in the United States as female parent of several cultivars.