Rush skeletonweed is a perennial that grows 1 to 4 feet (0.30-1.20 m) feet tall. The plant has a deep, extensive root system and stems with distinctive hairs (trichomes). Four to six inches (10-15 cm) up the stem, coarse hairs bend downward and the stem is smooth above
Sharply-toothed leaves form a rosette which withers as the flower stem develops. Other leaves up the stem are inconspicuous, narrow and entire. The leaves and stems exude a milky latex when cut or damaged.
The flower heads are scattered on the branches. They are approximately 3/4 inch (2 cm) in diameter and have 7 to 15 yellow, strap-shaped flowers. Flowers and the pale, brown to nearly black, eighth-inch long (2 mm)
Seeds are produced mid-July through frost. The seed is ribbed with tiny scaly projections on top and a long beak with numerous soft white bristles at one end.
Rush skeletonweed is an introduced Eurasian species which has infested several million acres in Idaho, Oregon, Washington and California. It inhabits well-drained, light-textured soils along roadsides, in wildlands, grain fields and pastures. It becomes established most easily in disturbed soils and is very difficult to control once it becomes established.
Rosettes resemble those of a dandelion, however, stems have red hairs at their base.
Yellow flowerheads, less than one inch wide. The strap-shaped petals have a flat end with distinct lobes.