The Ted R. Bradley Herbarium

Exploratory Hall, L109 and L110



Herbarium Prep Room, Exploratory Hall L109


Herbarium Research Collection Room, Exploratory Hall L110

What is an Herbarium?

A collection of dried, pressed plant specimens that are maintained for scientific reference. Specimens are prepared with archival-quality materials and are intended to last for centuries. Click here for what a specimen looks like.

Brief History of the Ted R. Bradley Herbarium

The George Mason University Herbarium was begun in 1967 by its first curator, Professor Ted Bradley. Dr. Bradley added thousands of collections over the course of his career. By the time he retired in 2003, he had expanded the collection to over 60,000 specimens of vascular plants, non-vascular plants and lichens. The herbarium is listed in Index Herbariorum under the acronym GMUF. Mason’s herbarium is tied with LYN as the fourth largest in the Commonwealth. Click here for map of Virginia’s herbaria.


Havala, a Mason undergraduate, creating a database of a portion of the herbarium as part of an independent study project.

Regional Focus and Organization

The majority of specimens (ca. 67%) are from Virginia, particularly Northern Virginia, and are separated in beige folders from other specimens in the cabinets. The remaining ca. 33% mainly derive from the southeastern US and are placed in yellow folders. However, international specimens, such as those from Canada, Puerto Rico, Andros Island (Bahamas), and South America, are further segregated into orange folders. The entire collection is arranged by family, alphabetically by genus and species, followed by geographical segregation at the species and sub-species level. The herbarium also maintains a library of identification keys, botanical journals and reference books.


Sara, a Mason graduate student, collecting Virginia Seashore Mallow (Kosteletzkya pentacarpos) in southern Maryland as part of her taxonomic revision of this species.

The Value of the Ted R. Bradley Herbarium for Research

The herbarium maintains a synoptic collection of Northern Virginia flora that is used for reference collection by Mason faculty and students as well as non-Mason biologists. The vast majority of these specimens are not duplicated elsewhere and are therefore irreplaceable documents of Virginia’s plant biodiversity heritage. The herbarium supports the ongoing research programs of several Mason professors and their student’s projects. Since 2000, the herbarium has supported thirteen Master’s and PhD research projects (see Table 1).


Table 1. Theses and dissertations produced by Mason students since 2000 that have relied on the Ted. R. Bradley Herbarium.

Masters’ theses

  • Oldham, Karoline. ongoing. Taxonomic revision and phylogeographic study of American Cow-wheat (Melampyrum lineare; Orobanchaceae).
  • North, Brittany. 2013. The response of the root and soil fungal communities to competition among Amphicarpaea bracteata, Onoclea sensibilis, and the invasive Microstegium vimineum in Northern Virginia.
  • Smith, Matthew. 2011. Vascular flora of Crow’s Nest State Nature Preserve. Project-based.
  • Alexander, Sara. 2010. A subspecific revision of North American saltmarsh mallow, Kosteletzkya pentacarpos (L.) Ledeb.
  • Baird, Kristen. 2009. The phylogenetics and historical biogeography of Leibnitzia Cass. (Asteraceae: Mutisieae): American species in an Asian genus.
  • Williams, Lisa A. 2004. Floristic survey of the Eastern Goose Creek watershed, Loudon County, Virginia.
  • Dee, Suzanne. ongoing. Structural and functional development of vegetation in mitigation bank wetlands created in the piedmont region of Virginia.
  • Dodge, John E. 2000. A floristic survey of the Potomac River watershed in Westmoreland County, Virginia, from Bridges Creek to Currioman Bay.
  • Lea, Christopher. 2000. Plant Communities of the Potomac Gorge and their relationship to fluvial factors.

Ph.D. dissertations

  • Dal-Forno, Manuela. ongoing. Systematics, phylogeny, and species taxonomy of the lichen genus Dictyonema.
  • Gostel, Morgan. ongoing. Origin and evolution of endemic Commiphora lineages of Madagascar.
  • Hollowell. Thomas H. 2005. Plant community structure, fire disturbance, and recovery in mangrove swamps of the Waini Peninsula, Guyana.
  • Strong, Mark T. 2004. An electron microscopy study of the outer pericarp surface of the achenes (fruits) of Rhynchospora (Cyperaceae) in the Guianas, South America, bearing on the delimitation of species and sections, and to clarify the taxonomy and distribution of species occurring in the Guianas.
  • Kelloff, Carol Lynn. 2002. Plant diversity of Kaieteur National Park, Guyana: Using plant data as a tool in conservation and development.


Recent external visitors to Mason’s collection include nature resource professionals from the Virginia Natural Heritage Program, NatureServe, US Geological Service, and Fairfax County and the City of Alexandria. Botanists from outside Virginia also access the collections through loans of specimens to their institutions. GMUF specimens are currently being used to support a range of non-Mason projects including a revised Flora of the Bahamas, a pollen flora of the Potomac River Basin, and the Flora of Virginia.


Mason undergraduates are shown here on a class trip to Shenandoah National Park as part of the field botany labs for BIOL345 – Plant Ecology. The herbarium provides teaching resources for six Mason courses.

The Value of the Ted R. Bradley Herbarium for Teaching and Scientific Outreach

In addition to supporting Mason student research projects, the herbarium provides teaching resources for BIOL103 – Introductory Biology, BIOL344 – Plant Diversity and Evolution, BIOL345 – Plant Ecology, BIOL520 – Systematics of Complex Angiosperm families), EVPP335 – People, Plants and Culture, and EVPP350 – Freshwater Ecosystems. The herbarium hosts tours for members for the Mason community, children’s groups such as Girl Scout troops, and various civic organizations. The herbarium has also sponsored a successful native plant rescue on campus that involved the local community.

Information for visitors

GMU policies and procedures for people wishing to access the herbarium are available for download here. Visitors should contact the director, Dr. Andrea Weeks, to make an appointment to visit the collection. Maps to Exploratory Hall and parking garages on the Fairfax campus of George Mason University can be found here.