CG Cookie has compiled a set of 40 high-quality nature textures.
CG Cookie has partnered with Gametextures.com to bring you some of the best tile-able textures around. This pack includes 40 textures, ready to drop right into your project. Each texture includes all the necessary maps to create stunning surfaces ideal for outdoor elements like rocky ground, grass, sand, snow, ice, and more.Included Texture Maps: Diffuse color, Gloss map, Height map, Normal map (including standard and inverted Y), and of course a Specular map.
The Ground and Foliage Shader & Texture Pack sells on the Blender Market for $45.