Xanthisma junceum is a species of flowering plant in the family Asteraceae known by the common names rush bristleweed or rush-like bristleweed.

It is native to northern Mexico and it occurs in the United States only as far north as San Diego County, California.

The linear leaves are mostly located at the base of the plant, each 1–2 cm long and toothed or cut into bristle-tipped lobes.

The inflorescence bears one or more flower heads lined with glandular, bristle-tipped phyllaries.

The fruit is a hairy achene 2–3 mm long tipped with a pappus.