About Helianthus ciliaris DC.
Helianthus ciliaris is a species of sunflower with the common names Texas blueweed and yerba parda. This species grows across much of the south-central and southwestern United States, ranging north from Texas to Kansas and west to California, as well as in northern Mexico, ranging west from Tamaulipas to Sonora and south to Durango and San Luis Potosí. It can also be found in other parts of North America as an introduced species, where it is often classified as a noxious weed. It is considered weedy even across most of its native range, growing easily in disturbed areas, on cultivated land, and along roadsides. It grows particularly well in moist areas like drainage ditches. Helianthus ciliaris is a perennial herb with distinctive blue-green foliage that reaches heights of 40 to 70 centimeters, or 16 to 28 inches. It has a tough, horizontally spreading root system that produces new plants at distances from the original parent plant, and can also sprout new growth after being fragmented. This means plowing the plant under the soil can actually help it spread. Its leaves vary in size, shape, and arrangement, but are generally narrowly lance-shaped, wavy, and lined with rough hairs along their edges. The plant's inflorescence holds a cluster of at least 35 yellow-tipped red disc florets, which is often surrounded by a fringe of 10 to 18 curling yellow ray florets, though some flower heads do not have ray florets.
