A smooth, branching perennial often growing in large colonies. Flowers open, compound umbels, bright yellow, in a more or less flat-topped display. Blooms April–June. Lower leaves once- or twice-ternately compound (in groups of threes). Upper leaves once-ternate or irregularly compound. Leaflets ovate, finely toothed; edges have a narrow white border.
Similar species: Heart-leaved golden Alexanders (Z. aptera) is scattered mostly south of the Missouri River. Its basal leaves are most often simple, less often once-ternately lobed or compound. Meadow parsnip (Thaspium trifoliatum) is also quite similar. It can be distinguished by its having the middle flower in each umbel slightly raised, on a little stalk. The middle flower in golden Alexanders is mostly stalkless and recessed. A surer way to distinguish between them is to examine the fruits: Those of Thaspium are strongly winged, while those of Zizia are unwinged or only ribbed or slightly winged.