The fungus herbarium, the second largest in the Western Hemisphere, comprises approximately 600,000 specimens. The collection was initially formed when the Garden purchased the herbarium of Job Bicknell Ellis (1829-1905), a pioneer in North American mycology, who built his collection of more than 100,000 specimens over 40 years. He not only collected extensively but also received material from collaborators across the U.S. and from many parts of Europe. All groups of fungi are represented in the Ellis Herbarium, with the greatest emphasis placed on plant pathogens and micro-fungi in general. The collection includes the types of 4000 new specimens described by Ellis and collaborators. Today, the Ellis herbarium is intercalated with the general fungal collection.