White Ash— Fraxinus americana

This chapter discusses the white ash, which appears similar to green ash but occurs in better-drained uplands and is common to midwestern successional habitats, particularly those following agriculture. White ash exists as three separate genetic lineages: a diploid, a tetraploid and a hexaploid. The chapter explains how a tetraploid white ash crossed with a diploid green ash and doubled its chromosome count could make a reproductively viable hexaploid pumpkin ash. The chapter considers white ash as the most abundant of the ashes as it has a broad geographic range. White ash, when young, is more shade tolerant than the other ashes, allowing it to regenerate in closed canopied forests more than the others.