About Hymenothrix dissecta (A.Gray) B.G.Baldwin
Hymenothrix dissecta is a North American flowering plant species in the Asteraceae family, commonly known as yellow ragweed and ragleaf bahia. It is native to the western United States, reaching as far north as the Black Hills of South Dakota and Wyoming, and also grows in northern Mexico, specifically in Baja California, Chihuahua, Coahuila, and Sonora. This species occurs in a range of habitat types, from dry mountain slopes to roadsides. It is an annual or biennial herb that grows a spindly, branching, erect stem, with a height ranging from 20 centimeters to well over one meter. Its stems are reddish and typically glandular. The small leaves are mostly found toward the base of the stem and are finely divided into linear lobes. The spreading inflorescence bears several flower heads, each lined with hairy, glandular phyllaries. Each flower head has a fringe of rounded yellow ray florets roughly half a centimeter long, surrounding a center of yellow disc florets. The fruit is a dark-colored achene 3 to 4 millimeters long. Any pappus present on the fruit is small and scale-like. American botanist Asa Gray first described this species as Amauria dissecta in 1849, from material collected in a valley between Guajuquilla and Mapimi in Chihuahua. Bruce Gregg Baldwin reclassified it into the genus Hymenothrix in 2016, giving the current accepted scientific name Hymenothrix dissecta (A.Gray) B.G.Baldwin.
