Hawkweed queen-devil
(Hieracium glomeratum)

Description:
The name Hieracium comes from the Greek 'hierax', meaning hawk; allegedly keen-sighted hawks of yore ate the sap of the brightly colored plants to sharpen their eyesight. In North America, invasive hawkweeds are an eyesore - and they are among the most troublesome weeds in the Pacific Northwest (PNW) (Wilson et al. 1997). The first invasive species, Hieracium aurantiacum, arrived in the region as recently as fifty years ago, probably from the western expansion of infestations from eastern Canada and the US during or shortly after the Second World War. There are now about 14 species of invasive hawkweeds in the PNW. Rapid spread of hawkweed has been possible because much of the land in British Columbia, coastal and northeastern Washington, northern Idaho, and northwestern Montana is considered susceptible to invasion by these aggressive weeds.

Hawkweeds are in the Tribe Lactuceae of the Family Asteraceae, having all strap-shaped (ligulate) flowers and a milky latex in stems and leaves. The genus Hieracium is divided into 3 subgenera (Strother 2006). Subgenus Chionoracium (formerly subgenus Stenotheca) represents the + 20 native species in North America. Subgenus Hieracium occurs in both North America and Europe. Two native species occur in the PNW; six species from central and eastern Europe also occur in the region. Subgenus Pilosella, entirely European in origin, represents most of the invasive species in the Pacific North West. A new species, Hieracium glomeratum, yellowdevil hawkweed, introduced from Europe, was identified from southeastern British Columbia in 2001.

• Mechanical: Not Known
• Biological: Fertilizers and soil fertility management have been used to effectively control hawkweeds in some areas, especially in new hawkweed infestations or where hawkweed density is relatively low.
• Herbicide: Herbicides are effective in suppressing hawkweeds but reinvasion occurs unless other plant species fill the gaps left by hawkweed removal.

For More Information:
Detailed information about hawkweed queen-devil is available at the Washington State Noxious Weed Control Board Web Site.