The Harvard University Herbaria & Libraries has been the centerpiece of plant biodiversity research at the University since the early 1800s. HUH collections are a major international botanical resource, and are frequently consulted by workers in systematics and in associated disciplines, including: ecology, morphology, biogeography, conservation, anthropology, phytochemistry, and especially for DNA sequencing related to phylogenetic investigation. The faculty and staff teach a variety of courses in their areas of expertise, and direct the research of graduate students and postdoctoral fellows who rely on the collections, laboratories, and library for their research.