Hoyt Arboretum Friends (HAF) is a membership-based, nonprofit organization working in partnership with Portland Parks and Recreation to support Hoyt Arboretum.

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Introducing the Hoyt Arboretum Herbarium

Under the leadership of Martin Nicholson, Hoyt Arboretum Collections Curator, we have established the Hoyt Arboretum Herbarium. Mandy Tu is the Herbarium Curator. Access our database with Garden Explorer.

What is an herbarium?

An herbarium is a natural science collections museum serving the community in furthering the understanding of biodiversity, conservation, education and research. It is a collection of preserved plant specimens used in a wide range of scientific disciplines. Like books in a library, herbarium specimens are targeted for conservation in perpetuity. These specimens may be whole plants or plant parts. The specimens will usually be dried, mounted on a sheet or in an archival plastic bag. Depending upon the material, specimens may also be kept in alcohol or other preservatives.

A voucher specimen is any specimen that serves as a basis of study and is retained as a reference. It should be in a publicly accessible scientific reference collection. Researchers submit voucher specimens used in a particular study to demonstrate precisely the source of their data for peer review purposes. A specimen includes as much of the plant as possible such as flowers, stems, leaves, roots, seed and fruit. Herbarium labels document flowering and fruiting time, geographical distribution, ecological conditions and associated species.

Herbarium voucher specimens are useful not only to taxonomists. Exsiccate (dried) collections are a critical source of data used by systematic botanists, ecologists, geographers, entomologists, conservation biologists, students and the general public. DNA preserved in dried specimens is useful in phylogenetics. Herbaria are also essential for the study of ex situ conservation, geographic distributions and the stabilizing of nomenclature (or name resolution) and often act as repositories of viable seed.  

An herbarium preserves historical records of change in vegetation through time. At times plants become extirpated in one area, or may become extinct altogether. In such cases, herbarium specimens can represent the only record of the plant's original distribution.  Environmental scientists make use of such data to track changes in climate and human impact. For conservationists, documented specimens provide data essential to estimating rarity and historical decline. Analysis of rare specimens are often used in the legal listing of species as vulnerable or endangered, locating potential habitats where a rare species may be found or where it might be recovered through ecological restoration.

Our herbarium project is focused on the determination of all trees in the Hoyt Arboretum, Leach Botanical Garden collections and regional rare and invasive species for education of land managers. As with any museum collection provenance - in this case, for plant family, genus and species - helps maintain the quality of our collections and provides useful taxonomic information about the collections as a whole. The Hoyt Arboretum Herbarium has initially focused on vouchering specimens of our living tree collections and is now including regional rare and invasive species collections. With this herbarium project Hoyt aspires to expand local species collection, local research opportunities and school-age education as well as adding to the global scientific body of species knowledge.

Hoyt Herbarium and Arboretum is an easily accessible regional taxonomic resource for the scientists of multiple agencies in the greater Portland metro area. We provide plant identification services and share our inventory of herbarium specimens for research with primary and advanced educators, visitors and students. In addition to serving Portland Parks & Recreation we serve a wide variety of community partners such as Leach Botanical Garden, the City of Portland Bureau of Environmental ServicesMetro Regional Government, university researchers and students. 

For more information please contact Herbarium Curator Mandy Tu or Arboretum Curator Martin Nicholson.