Stem: perennial; 2’ to 3’ tall; some branching above the middle; sparsely hairy below.
Leaves: mostly opposite; oval-linear, 3” by 3/4”; sessile; margins lobed 1/8” deep, the lobes finely toothed; few, long hairs above and below.
Inflorescence: raceme; flowers crowded; leafy bracts below each flower 3/8” long, finely toothed and with stiff, marginal hairs.
Flowers: corolla yellow, tubular, 7/8” long, upper lip curved downward; calyx two-lipped, 1/4” long, hairy on the inside at the base of each lip; flowering from mid-August to mid-September.
Fruits: capsules, 3/8” long, two-lipped; maturing within the calyx; fruiting begins in late August.
Habitat: frequent on wet to moist prairies, in marshes, and in wet, open woods; becoming very infrequent in the western and southern parts of its range in Iowa.