Plants annual or biennial, (20-)40-100(-150) cm, glabrous. Stems erect, simple or branched. Leaves (cauline subsessile dis-tally); blade oblong-spatulate, 5-10(-15) × 0.5-2 cm, margins entire or subentire (flat or crispate), surfaces glabrous or, sometimes, with 1-2 conical glands basally. Racemes 10-50 cm; bracts persistent, lanceolate-attenuate, 2-3.5 mm (4-5 mm in fruit). Pedicels 1-3 mm. Flowers: sepals persistent, 4, not reflexed in fruit, lanceolate-ovate, 1-2.5 mm; petals 4, yellowish, 2-4 mm, rounded-clawed, adaxial ones irregularly lobed; stamens 20-40; filaments persistent, 2-3 mm, glabrous; intrastaminal nectary-discs glabrous; anthers 0.5-0.6 mm; placenta forked distally. Capsules erect, 3-carpelled, ovoid to subglobose, 3-5 × 4-6 mm, apically 3-toothed, usually glabrous. Seeds 0.6-1 mm, glossy, smooth. 2n = 24, 26.
Flowering (Jan-)Mar-Sep(-Dec). Waste ground, roadsides, fields, railway yards, ballast ground, basic and sandy soils; 0-2900 m; introduced; B.C., N.S.; Calif., Colo., Conn., Del., Ill., Ind., Iowa, Md., Mass., Mo., N.J., N.Y., Ohio, Oreg., Pa., R.I., Tex., Wash.; Europe; sw Asia; n Africa; n Atlantic Islands; introduced also in n, c Mexico.
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.
Author: The Morton Arboretum
With entire lvs, short pedicels, and 4 pet that are merely toothed or cleft, is occasionally adventive from Europe.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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