Invasive species at the Weippe Prairie Site

Students and volunteers participating in the Camas Citizen Science Monitoring Program also help collect data on invasive species found at Weippe Prairie. Invasive species are non-native plants that, when moved to new areas, tend to dominate and out-compete existing species for light, water, and other vital resources. They can threaten the existence of native species such as camas. The two invasive species monitored at the Weippe Prairie are orange hawkweed (Heiracium aurantiacum) and sulphur cinquefoil (Potentilla recta).

Orange hawkweed is a noxious weed in that once it establishes itself in an area, nothing else will grow. Hawkweed has hairy, spatula-like leaves that grow out of the ground in rosettes. In bloom, the flowers are bright orange. Generally it is found in patches, and occasionally alone. Farmers tend to have the most problems with this weed. To eradicate these weeds, the plants must be sprayed and covered in plastic bags; then the roots need to be completely pulled out. In 2009 Weippe Prairie was sprayed for hawkweed.

Sulphur cinquefoil is relatively hard to distinguish from the native species slender cinquefoil (Potentilla gracilis) when not in bloom. This plant grows palmate leaves with five to seven leaflets. Its flowers are light yellow in color, as opposed to the mustard yellow petals of the native slender cinquefoil, and there are long, stiff hairs on the stem that protrude perpendicular from the stem. Its leaves tend to be a lighter green than slender cinquefoil.

For an identification guide for these two invasive species, Invasive_Spp_PlantKey_20100408.pdf.

The National Park Service has programs in place to eradicate these invasive weeds. Visit www.webs.uidaho.edu/nsan/aliens/alienhome.htm for invasive species-themed lesson planning materials.