Gumweed, a dark green leafy plant, also is called tarweed or rosinweed because its leaves are sticky.
Native to the western United States, gumweed (Grindelia) grows on prairies and plains, along roadsides and in old fields, pastures, and other dry, open places. The plant, a member of the sunflower family, reaches heights of up to three feet.
Gumweed has openly spaced branches on the upper part of its stems, which are stiff and sometimes reddish.
Many bright yellow flowers are borne individually at the ends of the upper branches. The flowers are about 1 1/2 inches wide and have 25 to 40 petals around a small, brownish disk. Leaves are oblong with sharp-edged teeth pointing forward. Curly cup gumweed (Grindelia squarrosa) is the most common variety of the plant. Gumweeds are toxic and become more so depending on their soil.
Nevertheless, gumweed has been used medicinally for centuries. According to the Audubon Society's "Field Guide to North American Wildflowers," Spanish New Mexicans, who believed in magical numbers, "boiled three times three buds of flowers in three pints of water until only one pint remained, and drank a glassful three times a day for kidney disorders."