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Help Collect Noxious Weeds for Science

Butterfly Bush photographed by Ben Legler.

Butterfly Bush photographed by Ben Legler. Copyright 2006. All rights reserved.

In a major effort to increase the scientific collections of invasive species in Washington’s major herbaria, WNPS hired Peter Zika to examine the current holdings of the University of Washington’s herbarium in Seattle (WTU), and draw up a list of the noxious weeds that have been reported from a county but not documented with a herbarium collection. (Complete report, Douglasia article and tables).

How did we assemble a list of weeds to document? Estimates suggest that perhaps 20% of the Washington flora consists of exotic introductions. From this, we chose to address those species legally classified as "noxious weeds" in state statutes and regulations (Chapter 16-750 WAC). See the state noxious weed list: http://www.nwcb.wa.gov/nwcb_nox.htm

This totals 162 species of interest to this project. Maps of their reported county-by-county distribution were compiled by Greg Haubrich (2002) of the Washington State Department of Agriculture. Zika used these maps to compare with herbarium collections at the University of Washington.

To identify what weed specimens are needed from each county, click on the counties of a map on Noxious Weed Collections Needed.

As a botanical community, we need to beef up our herbarium holdings of noxious weeds. These specimens are important for everyone who studies and teaches the flora. They allow comparison of native and non-native species in the same genus, an important distinction to make in large complex genera like thistles (Cirsium), water milfoil (Myriophyllum), and hawkweeds (Hieracium). The locality information with each herbarium specimen also allows accurate targeting of weed control efforts, both on the ground, and in determining regulatory lists.

This is where you can contribute, by making collections of these weeds, and donating the specimens, with good location information, to the University of Washington herbarium. Duplicates will be distributed to the Washington State University’s herbarium in Pullman, as well as other research institutions, where they will form an important resource for students of systematics, evolution, floristics, and exotics.

To help you get started:

Complete Report by Peter Zika, December 2005

Existing Herbarium Documentation for Washingtons Noxious Weeds (Word)

Douglasia Article by Peter Zika, Winter 2006

Help Collect Noxious Weeds in Washington (PDF)

Tables from Douglasia Article:

Table 1. Noxious Weed Genera with Native Members in Washington (PDF)

Table 2 County Vouchers Needed, arranged alphabetically by species (PDF) (also found on Noxious Weed Map)

Table 3 County Vouchers Needed, arranged alphabetically by county (PDF) (also found on Noxious Weed Map)

Table 4. Class A Noxious Weeds (PDF)

Table 5. Class B Noxious Weeds (PDF)

Table 6. Class C Noxious Weeds (PDF)

Table 7. Monitor Weeds (PDF)

Table 8. Facts and Figures About Noxious Weeds (PDF)

Table 9. Washingtons Most Wanted Noxious Weed Collections (PDF)

Table 10. Useful Web Sites (PDF)



Updated: April 25, 2016
Copyright 2000-2017 Washington Native Plant Society. All rights reserved.

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