The potential of grasslands to deliver ecosystem services and mitigate some of the impacts of climate change is increasingly being recognised. Backcross hybrids between the stoloniferous Trifolium repens L., and the related rhizomatous species T. ambiguum M. Bieb have been produced using T. repens as the recurrent parent. The differences between parental species and the backcrosses in root morphology were studied in 1m long pipes. The parental species differed in root distribution and in root weight distribution, with root weight of T.ambiguum significantly greater than T. repens in the 0.1m to 0.5m root zone. The backcrosses exhibited root characteristics intermediate between the parents. The extent to which such differences in root architecture may influences soil structure and deliver ecosystem services is discussed.