Golden Alexanders (Zizia aurea) vs. Meadow Parsnip (Thaspium trifoliatum)

These perennials can overlap in habitat and are easily confused where their ranges overlap, especially the yellow-flowering Thaspium trifoliatum var. aurea which is more common in most regions. The species are easily distinguished by seeds and basal leaves, and with a close look, by flowers. Zizia aurea ranges much farther north and slightly farther west, has slightly higher light needs, prefers moister conditions, and is more restricted to a narrow range of neutral-to-slightly acidic soil pH. Thaspium trifoliatum ranges into deeper shade, occurs in a broader range of soil pH, and prefers drier conditions.

View Full Guide