We generated SNP genotype data from two endangered plant species, Pimelea spicata and Eucalyptus sp. Cattai. For each, we genotyped plants from a population that was 'condemned,' or that would soon be destoyed. We used the genotype data to design ex situ germplasm collections that preserved the diversity in the condemned populations, in ways that were optimized. Here, we provide an archive of these SNP genotype data, and the code that was used to analyse these data, including the optimizations.