Trioncinia patens is a species of flowering plant in the family Asteraceae.

Trioncinia patens is a perennial plant that typically grows up to 50 cm (20 in) tall.

It has a thick woody taproot and several stems arise from the caudex.

The alternate leaves are mostly basal, and are up to 7 cm long; the petioles are up to 4 cm long; the lamina is pinnatifid, and is up to 3 cm long and 2 cm wide; the narrow leaf segments are 1 to 1.5 mm wide, and have a short, sharply pointed tip at the apex.

The inflorescences are branched in the upper half of the plant, the peduncles are 4 to 12 cm (1.6 to 4.7 in) long, often with 1 or 2 bracts in the upper half.