Wear is major stress that limits the function and quality of intensely trafficked putting greens. Creeping bentgrass (Agrostis stolonifera L.) and velvet bentgrass (Agrostis canina L.) genotypes (cultivars) are used on golf courses as putting surfaces, however, their tolerances and associated mechanisms to wear have not been studied. The objectives of this research are (i) evaluate wear tolerance among Agrostis genotypes and (ii) identify specific mechanisms (plant factors) associated with wear tolerance. Wear was assessed in the field on 27 Agrostis entries grown on a USGA sand rootzone as part of the 2003 NTEP Putting Green test. Plots were mown daily at 3.2 mm, fertilized at 24.5 kg N/ha per growing month, and irrigated to prevent stress. Significant wear injury was applied on all entries using 50 passes with a walk behind mower fitted with a grooming brush adjusted to operate in the free-floating position. Wear treatments were applied on 27 October, 2005, 16 June and 25 October, 2006. Wear injury was assessed using a visual rating scale (1 to 9, 9=no injury). Velvet selections exhibited greater wear tolerance compared to creeping bentgrass in 2005. The top and bottom performing entries in wear tolerance were selected for further study, which represented 7-velvet and 7-creeping bentgrass genotypes, respectively. Wear was reapplied in the spring and fall of 2006 and results were similar to those observed in 2005. Twelve morphological and anatomical characteristics were measured in the greenhouse on the 7-velvet and 7-creeping bentgrass selections. Superior wear tolerance with velvet genotypes was closely associated with a more upright tiller and leaf growth-habit, higher shoot (tiller) density, and greater total cell wall content and cell wall constituents. Total cell wall content and cell wall constituents accounted for as much as 90% of the total variation in wear tolerance in the field.