This is the first genome assembly release of the British Ash Tree Genome project. It is based on 4.3X coverage of the ash genome by Roche 454 sequencing, and assembled using Newbler and the CLC Genome Finishing Module by Lizzy Sollars. The options used in Newbler to make this assembly were: ‘-sl 32’, ‘-urt’, ‘-m’, ‘-e 5’. Ten other assemblies with different options were carried out in Newbler, and this assembly was selected on the basis of higherst contig N50 length and highest number of complete hits of core eukaryote genes using CEGMA (a search for 248 ultra-conserved core eukaryote genes). Statistics for this assembly are as follows: