The nearly 4 cm flowers are large and violet, with a wide lower lip that has at its center two distinct white lines leading insects to the pollen and nectar glands inside. The stalks are square when young, becoming round when mature, with two distinct dark purple-brown lines running up the length of the stalk. The plant is sometimes confused with Salvia candelabrum, which has undivided leaves [citation needed] as compared to S. interrupta, due to the similarity of the flower stalks.