Biennial herb 0.5 - 1.5 m tall Stem: few-branched. Leaves: alternate, short-stalked, 3 - 12 cm long, 0.4 - 1.5 cm wide, lance-shaped, tapering to the base. Flowers: borne in a dense terminal infloresecence (raceme) to 35 cm long, yellow, small, with four sepals and four unequal petals, the uppermost petal largest and the others progressively smaller, upper petals four- to eight-lobed, lower petals unlobed to four-lobed. The stamens are borne 20 to 30 on a fleshy disk and are clustered on one side of the flower, and the ovary is three- to four-lobed at the tip. Fruit: a nearly spherical capsule, 3 - 4 mm long, 5 - 6 mm wide, with a three- or four-lobed tip that opens at maturity, containing blackish kidney-shaped seeds.
Similar species: Reseda alba and Reseda lutea have deeply divided leaves and capsules that are longer than wide. Reseda odorata has very fragrant flowers with six yellowish white to greenish flowers.
Flowering: summer
Habitat and ecology: Introduced from Europe, this species is rare in the Chicago Region.
Occurence in the Chicago region: non-native
Notes: This species used to be grown for a yellow dye.
Etymology: Reseda comes from the Latin word resedo, meaning "to heal." Luteola means yellowish.