Heracleum maximum

Cow Parsnip

Cow Parsnip, Superior National Forest, Photo © 2000 by Earl J.S. Rook
Cow Parsnip
Superior National Forest
Photo © 2000 by Earl J.S. Rook

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Heracleum, from the Latin, Herâclêus, "of or belonging to Hercules" (itself derived from the Greek)
  • maximum, from the Latin, maximus, "large, great, high, extensive", a reference to its great size.
  • Common Name, from its perceived similarity to the parsnip, and its appeal to cattle.
  • Other common names include Common Cow Parsnip, Poochki (Russian, commonly used in Alaska), Yerba del Oso


  • Kingdom Plantae, the Plants
    • Division Magnoliophyta, the Angiosperms (flowering plants)
      • Class Magnoliopsida, the Dicotyledons
      • Subclass Rosidae
        • Order Apiales
          • Family Apiaceae (Umbelliferae), the Parsley and Carrots, 2850 species in 275 genera of global distribution but mostly north temperate regions. Includes the common herbs anise, carrot, celery, coriander, dill, fennel, parsley, and parsnip, as well as the highly toxic hemlocks.
            • Genus Heracleum, the Cow Parsnips
  • Taxonomic Serial Number: 502953
  • Also known as Heracleum lanatum, Heracleum sphondylium var. lanatum, Heracleum sphondylium ssp. montanum
  • Family Apiaceae characterised by alternate leaves, widening at the base into a sheath that clasps the stem. Stems often furrowed. Flowers usually compound, almost always concentrated in flat-topped umbels. Flowers have 5 petals, usually uneven, and 5 stamens. Seeds and fruit form below where the petals and stamen originate. Fruit two-chambered, separating into two, single-seed fruits at maturity. Some part of the plant usually has a strong aroma, due primarily to various oils produced by the plant.


  • A native, perennial forb, 3'-10' tall.
  • Leaves rough/hairy, palmately compound, large, 12"-18", divided into 3 segments, leaflets coarsely toothed; broad wing at the base of the leaf stalk.
  • Stem erect, branched, rough/hairy, hollow, grooved, and leafed.
  • Roots a stout taproot or a cluster of fibrous roots.
  • Flowers white/cream, with a sweet fragrance. Five petals, not all the same size, up to 1/3" long; in broad, flat-topped cluster of clusters at the top of short stalks. Blooms mid-summer in the North Country.
  • Fruit egg-shaped, 3/8"-1/2" long, 1/4"-3/8" wide; with 4 conspicuous vertical purple lines.
  • Seed in tight pairs, often conspicuously ribbed, and sometimes winged, flattened on one side, rounded on the other, with distinct ridges. Stong, unusual odor.


  • Identifiable as one of the Apiaceae by its broad, flat flower clusters, hollow stem, and clasping leaves.
  • Distinguished from all other white-flowered members of the family by its stout growth form; huge, hairy, palmately lobed leaves; and fruits marked with four vertical purple lines.


  • Newfoundland to Alaska; south to California, New Mexico, Kansas, and Georgia; also Siberia.
  • In July, look for Cow Parsnip in bloom in roadside ditches along Highway 61 on the North Shore, the Gunflint Trail, and the forest roads of the Superior National Forest. It's unmistakable, even at 55 MPH.


  • A variety of habitats including woodlands, forest openings, grasslands, and riparian areas such as wet meadows, stream terraces, alluvial benches, floodplains, and stream and lake margins; also disturbed areas and along roadways. A wetland species; it grows best in moist, shaded areas but can also be found in open woodlands and clearings.
  • Grows best on moist to semiwet soils with good drainage. Best soil texture loam and sandy loam derived from limestone and shale, but occurs on clay, clay loam, and gravelly substrates as well.
  • Occurs in successional and climax communities.
  • Early successional in meadow or disturbed sites, on moist to wet, high organic, nitrogen rich soils, bank seeps; a widely distributed plant.
  • Shade tolerant but dominates in sun, sometimes forming dense colonies.


  • Probably killed or top-killed by fire.



  • Young leaf stalks and stems, before flowering, were eaten like stewed celery. Native Americans of the northern US ate the peeled stalks raw or cooked.
  • The blossoms were steeped in oil and rubbed on the body by native North Americans to keep off flies and mosquitoes.



  • Reproduces by seed, forming a low-growing rosette, with a large, fleshy taproot its first year.
  • The potential to regenerate vegetatively is not clear.


  • By seed.


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Said to be excellent kid habitat, seasonal screen, or buffer for a backyard wetland meadow.
  • Energetic in full sun, does well in 60% shade.



  • Some North Country members of this family are poisonous, including the Water Hemlocks (Cicuta bulbifera and Cicuta maculata); some, like Cow Parsnip, are irratating to the skin; handle unfamilar plants with caution.
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Last Updated on 2 November, 2002