Reseda alba
Sp. Pl. 1: 449. 1753.
Plants annual or biennial (perennial), 30–90 cm, glabrous. Stems erect, usually branched. Leaves (cauline shorter distally); blade ovate to ovate-oblong, pinnatisect (lobes 4–15 pairs, lanceolate-oblong), 3–15 × 3–5 cm, (base attenuate), margins entire or repand to raggedly toothed, surfaces glabrous. Racemes (dense) 20–40 cm; bracts persistent, lanceolate-linear, 3–3.5 mm. Pedicels 2–8 mm. Flowers: sepals persistent, 5(–6), not reflexed in fruit, lanceolate-linear, 2–2.5 mm; petals 5(–6), white, (3.5–)4–6 mm, subrounded-clawed, adaxial ones 3-lobed; stamens 10–14; filaments persistent, 2–3.5 mm, glabrous; intrastaminal nectary-discs papillose; anthers 1–2 mm; placenta entire. Capsules erect, 4-carpelled, cylindric to ovoid-oblong, 8–14 × 4–6 mm, apically 4-toothed, glabrous or ribs papillose. Seeds 1–1.3 mm, dull, finely papillose. 2n = 40.
Phenology: Flowering May–Aug(-Nov).
Habitat: Muddy shores, dunes, waste places, railroad ballasts, roadsides, basic soils
Elevation: 0-800 m
Distribution
B.C., Man., Ont., Que., Sask., Ark., Calif., Conn., Del., Ill., Kans., Maine, Mass., Mich., N.H., N.J., N.Y., Ohio, Oreg., Pa., Vt., Wash., s Europe, sw Asia, n Africa, introduced also in South America, s Africa, Australia.
Discussion
Selected References
None.