Xanthisma gracile

Xanthisma gracile is a species of annual flowering plant in the family Asteraceae known by the common names slender goldenweed and annual bristleweed.

Range and habitat

It is native the southwestern United States and northern Mexico, where it grows in the deserts and plateaus.

Growth pattern

It is a bristly annual herb growing erect up to 45 cm tall.

Leaves and stems

The oval or oblong leaves are 1–3 cm long and divided into lobes or teeth tipped with bristles.

Flowers and fruit

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.

Genetics

Xanthisma gracile has extra chromosomes that do not have any functional genes, and about which little is known. Its chromosome count is given as 2n=4 by Munz and Keck.