Xanthisma gracile[1] is a species of annual flowering plant in the family Asteraceae known by the common names slender goldenweed and annual bristleweed.[2]
It is native the southwestern United States and northern Mexico, where it grows in the deserts and plateaus.
It is a bristly annual herb growing erect up to 45 cm tall.
The oval or oblong leaves are 1–3 cm long and divided into lobes or teeth tipped with bristles.
The inflorescence bears one or more flower heads lined with pointed, roughly hairy phyllaries. The head has a center of many yellow disc florets and a fringe of 16 to 18 yellow ray florets roughly a centimeter long. The fruit is a woolly achene 2 to 3 millimeters long tipped with a pappus.
Xanthisma gracile has extra chromosomes that do not have any functional genes (B chromosomes), and about which little is known.[2]