Much-branched, upright perennial, without hairs. Flowers minute, in compound, flat umbels, dark yellow, rarely purple or brownish purple. The central floret of each umbellet is slightly raised, on a stalk. Blooms April–June. Basal leaves simple, heart-shaped or only once-divided. Stem leaves on long stems (petioles) divided into 3 pointed, egg-shaped, finely toothed leaflets with a rounded base. All leaflets have a very narrow yellowish-white margin, a ready identification characteristic.
Similar species: Our other meadow parsnip species, T. barbinode, lacks the pale borders of the leaves. Golden Alexanders (Zizia spp.) are similar, but they don’t have the middle flower in each umbel slightly raised; instead, that floret is mostly stalkless and recessed. A surer way to distinguish between these genera is to examine the fruits: Those of Thaspium are strongly winged, while those of Zizia are unwinged or only ribbed or slightly winged.