The United States National Herbarium (US) maintains a world-class research collection of all major groups of plants (bryophytes, ferns, gymnosperms and angiosperms) as well as algae (esp. marine algae and diatoms) and lichens. Our vast collections of over 5 million specimens are accessible, both online and in person, to anyone with a research question related to our collections. Our Type Herbarium is one of the largest in the world. Visiting researchers include botanists, artists, historians, and students.