A major historic and botanic resource, the 7,700 watercolors in the USDA Pomological Watercolor Collection are preserved in NAL's Special Collections. Selected images are on permanent exhibition on the first floor of the library. USDA Pomological Watercolor Collection Development of new varieties is a continuous process as plant breeders build on existing varieties to improve or add valuable genetic traits. While color photography has made it simple to document new varieties, depictions can be artistic and valuable as scientific documentation. As in the early days when hand colored drawings served as documentation, USDA continues to make important contributions in the development of new and improved varieties for the benefit of producers and consumers.
New varieties are on permanent exhibition on the first floor of the library.