State Weed Board Proposes 1999 Noxious Weed List.

OLYMPIA, Wash.--(BUSINESS WIRE)--Nov. 13, 1998--Four new plants may be added to the noxious weed list, six species may be deleted, and control requirements may be changed for 15 others, the State Noxious Weed Control Board announced today.

Public comment on the proposals will be heard from 9 a.m. to 10 a.m. Nov. 17 at the Grant County Public Works Building, 124 Enterprise Street S.E., Ephrata.

"Noxious weeds are non-native, invasive plants that are highly destructive, competitive or difficult to control," said Lisa Lantz, executive director of the State Noxious Weed Control Board. "They were introduced without their natural predators, so they can spread rapidly to cause tremendous damage to agriculture and our natural resources."

There are 109 plants on the noxious weed list in Washington. The list is the basis for weed control efforts in the state. It is reviewed and revised annually.

Spurge flax and eggleaf spurge are proposed for the Class A noxious weed list. Class A weeds have very limited distributions or are new invaders that pose a serious threat to the state. Local weed control programs must ensure that landowners eradicate all Class A noxious weeds.

-- Spurge flax (Thymelaea passerina) has been found in Okanogan County. It has taken over native range and is not palatable to animals. The plant appears capable of impacting many habitats, ranging from seasonal wetlands to arid rangeland.

-- Eggleaf spurge (Euphorbia oblongata), a close relative of the destructive leafy spurge, has been found in San Juan County. It has been invasive, competitive, and very difficult to control.

Policeman's helmet is proposed as a Class B noxious weed. Class B weeds are non-native, invasive species that are limited to portions of the state. Weed control is mandatory in regions where they are not yet widespread. In regions where they are widespread, county noxious weed control boards and weed districts may require control if they feel it is a local priority.

-- Policeman's helmet (Impatiens glandulifera) has been observed in scattered locations, primarily in western Washington. The plant invades wet areas and may displace native species. This Asian native has already invaded much of Europe and is considered one of the "top 20" non-native plants in Britain because of its distribution and abundance.

Giant knotweed is a proposed addition to the Class C list. Class C weeds are non-native, invasive species that are widespread in the state. Long-term programs of suppression and control are strictly the option of the local boards, depending upon local needs and the feasibility of control in local areas.

-- Giant knotweed (Polygonum sachalinense) is closely related to Japanese knotweed, a Class C weed. The plant has an extensive root system that allows it to take over sites by dominating native or beneficial plants. Unlike Japanese knotweed, giant knotweed produces viable pollen. The two species can cross to produce fertile, aggressive, hybrid plants.

The board has proposed deleting six species from the noxious weed list. Monitoring of three species (Venice mallow, unicorn-plant, and hybrid deadnettle) indicates these plants have not established and spread in Washington. Three other species (bittersweet nightshade, common mullein, and bull thistle) are so widely distributed in Washington that local weed programs no longer target them for control.

Changes in control methods are also proposed for 15 listed noxious weeds. Saltcedar would be listed as Tamarix ramosissima and moved from the Class C list to the Class A list. Mouseear hawkweed would be moved from the Class A list to the Class B list, and four Class C species (wild chervil, wild carrot, garden rocket, and dwarf snapdragon) would be moved to the Class B list. In addition, changes would be made to the state-mandated control areas for nine Class B species: rush skeletonweed, herb-Robert, kochia, perennial pepperweed, Dalmatian toadflax, garden loosestrife, purple loosestrife, wand loosestrife, and gorse.

Along with changes to the weed list, the Weed Board proposes to update its mission statement to make it more concise and to reflect recent changes in the state weed statute, Chapter 17.10 RCW.

For a copy of the proposed changes, or to submit written comments, contact Lisa Lantz, Executive Director, Washington State Noxious Weed Control Board, 1851 South Central Place, Suite 211, Kent, Washington 98031-7507. Written comments may be sent by FAX to 253/872-6320 or by e-mail to [e-mail].