Mentzelia pectinata is a species of flowering plant in the family Loasaceae known by the common name San Joaquin blazingstar.

Mentzelia pectinata is an annual herb producing an erect, green stem up to about half a meter tall.

The leaves are up to 12 centimeters long in the basal rosette and divided into comblike lobes, and those higher on the stem are reduced in size.

The inflorescence is a cluster of flowers with orange to yellow petals up to 2 centimeters long and often marked with red near the bases.

The fruit is a narrow, straight utricle up to 3.5 centimeters long which contains many tiny, angular seeds.