Erythranthe glaucescens is an annual herb varying in maximum height from 6 to 80 centimeters. The stem is hairless and waxy. The oval to rounded leaves are up to 7 centimeters long and are sometimes borne on petioles. The inflorescence is a raceme of flowers with a distinctive pair of bracts completely fused around the stem to form a rounded disc up to 4.5 centimeters wide. The flowers are up to 3.5 centimeters long, spreading at the mouth into an upper lip with two notched lobes and a lower lip with three. The flower often has red spotting in the mouth.
Erythranthe glaucescens is a species of monkeyflower known by the common name shieldbract monkeyflower. It was formerly known as Mimulus glaucescens.