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Based on mutant phenotypes the <i>MONOPTEROS (MP)/Auxin Response Factor 5 (ARF5)</i> gene acts in several developmental processes including leaf vein development. Since overlapping functions among <i>ARF</i> genes are common, we assessed the related <i>ARF 3-8</i> and <i>19</i> genes for potential overlap in expression during vein development using in-situ hybridization. Like <i>MP/ARF5, ARF3</i> was expressed in preprocambial and procambial cells. <i>ARF7</i> was also expressed in procambial cells, close to and during vein differentiation. <i>ARF19</i> was expressed in differentiating vessel elements. To assess if genes with vein expression have overlapping functions, double mutants were generated. While <i>arf3, 5</i> and <i>7</i> mutants formed leaves normally, double mutant combinations of <i>mp/arf5</i> with <i>arf3</i> or <i>arf7</i> resulted in a breakdown of leaf formation. Instead, novel structures not present in any of the single mutants formed. The results implicate <i>ARF3</i> and <i>ARF7</i> in rosette leaf formation and suggest that their functions overlap and act in parallel with <i>MP/ARF5</i> in this process. The observed vascular expression patterns suggest unique functions (<i>ARF7</i> and <i>19</i>) and potentially overlapping functions (<i>ARF3</i> and <i>5</i>) in vein development. Since <i>arf3 arf5</i> double mutants do not form leaves, assessment of their potential combined action in vein development will require the use of conditional mutants.