The no leaf mark phenotype in red clover (Trifolium pratense) is imparted by a homozygous recessive genotype at a single locus. Several genes are involved in the expression of leaf mark phenotypes, consequently extensive variation occurs among plants for area and intensity of the variegation that produces a range of leaf-mark phenotypes. Leaf marks range from tiny areas of barely discernible variegation in the centers of leaflets to conspicuous chevrons that traverse the leaflets of red clover. Cultivated and wild populations of red clover vary widely for frequency of plants with no leaf mark. Our objective was to evaluate three leaf-mark morphs (i.e., no mark, slight mark, and prominent mark) across four cultivars for forage production and persistence in spaced-plant nurseries transplanted into Kentucky bluegrass sod (Poa pratensis) in eastern South Dakota. Year (2005 and 2006), cultivar, and the cultivar x leaf mark interaction effects were significant for forage production. For the cultivar Redlangraze, the no mark phenotype produced 20% more forage than the prominent mark phenotype; whereas, for the cultivar Robust the prominent mark phenotype produced 25% more forage than the no mark phenotype. Persistence will be evaluated in 2007.