The broom-weed is closely related to the rabbit-brush which is so abundant in West Texas and New Mexico. The Texas rabbit-brush (_Gutierrezia texana_) of West Texas is so much like the broom-weed that only a close observer can distinguish them. Both have 5-8 flowers with strap-shaped corollas in the outer part of the head and a few tubular flowers in the center; both bloom in the late summer and fall.
[Illustration: CAMPHOR DAISY TEXAS GUMWEED]
Camphor Daisy (_Heterotheca subaxillaris_), so called because of the camphor-like odor of the rough foliage, is a common summer pest to the farmer. The plants often grow 3 feet high and are much branched, bearing heads of golden-yellow flowers nearly an inch across. The upper leaves are broad and clasping, but the lower are narrowed at the base. The scientific name refers to the dissimilar fruits of the ray and disk flowers, those of the ray flowers having no bristles. It ranges from Delaware to Arizona and Mexico.
Texas Gumweed (_Grindelia texana_) belongs to a group easily recognized because of its sticky, bur-like heads and thick leaves. This one is common on rocky limestone slopes in Central Texas in the fall and ranges to Southwest Missouri. The wand-like stems, covered with the overlapping leaves, are topped by large heads of yellow flowers. Many gumweeds are found in Texas. Some of them were used to relieve colds, asthma, and rheumatism.
Big Gumweed. Saw-Leaf Daisy (_Prionopsis ciliata_) is easily recognized by its straight, stiff stalks which are closely covered with broad oval leaves. Dense masses of the sentinel-like plants may be seen along fence-rows in North-central and West Texas in August and September. It ranges north to Kansas and Missouri. The stems are topped by short clusters of large heads, 2-3 inches broad. The leaves are thick, gummy, and closely beset with bristle-tipped teeth. Sometimes an injury to the stem may cause it to become widely branched.
The scientific name means “resembling a saw” and refers to the leaf-margins. It is not a true gumweed but has similar bur-like heads. It differs from the gumweeds in having several unequal hair-like bristles on the seed, whereas the seeds of gumweeds have 2-8 stiff bristles.