2. Zizia aurea (L.) W.D.J. Koch (common golden Alexanders, common meadow parsnip)

Z. aurea f. obtusifolia (Bissell) Fernald

Pl. 214 f, i; Map 894

Stems 30–110(–150) cm long. Basal leaves with the blades 4–14(–20) cm long, 1 or 2 times ternately compound, the leaflets 1–12 cm long, broadly ovate to oblong-obovate or lanceolate, narrowed to rounded (often unequally) or cordate at the base, sometimes with 1 or 2 lobes toward the base. Stem leaves similar to the basal leaves, gradually reduced toward the stem tip, becoming more finely divided with somewhat narrower leaflets and/or segments, the uppermost often only ternately 1–3 times deeply lobed. Rays 10–21, 0.6–5.0 cm long. 2n=22. April–June.

Scattered nearly throughout the state, but apparently absent from most of the Mississippi Lowlands Division (eastern U.S. west to Montana and Texas; Canada). Bottomland forests, mesic upland forests, upland prairies, glades, savannas, banks of streams, rivers, and spring branches, bases, ledges, and tops of bluffs, and rarely fens; also roadsides.

Zizia aurea grows in the widest variety of habitats of any of the Thaspium and Zizia species in Missouri. It can be grown easily in gardens from seed and the foliage and flowers are quite attractive, but if allowed to produce seed it can become overly aggressive.