The University of Washington Herbarium (also known as WTU) is an international resource for research into the diversity, distribution and ecology of Pacific Northwest vascular plants, non-vascular plants, fungi, lichen, and algae.
With over 600,000 specimens currently in the collections and between 5,000-10,000 specimens added annually, WTU is one of the largest herbaria in the region. A history of WTU can be found here.
Support from the National Science Foundation's Biological Research Collections program (2003-2007) led to our databasing over 120,00 Pacific Northwest vascular plant specimens, which are available through our online database. This funding also supported creation of the Consortium of Pacific Northwest Herbaria website, which provides access to specimen data and digital resources from throughout the region.
A tool for mapping the distributions of vascular plant species in the San Juan Islands.
A map of Washington state showing all vascular plant specimen localities in the WTU Database.
Photos, distribution maps, and descriptions for Washington's vascular plants and lichens.
A working checklist of the vascular plants of Washington State.
A search portal providing access to collections held by herbaria throughout the region.
An interactive mapping tool that displays ranges of weeds and invasive plants in the state.
Access WTU's online resources for Washington State.
Learn about of the fungi of the Puget Sound Basin.
WTU is producing an updated Flora of the Pacific Northwest.