Heracleum maximum
Common Name(s):
Previously known as:
- Heracleum douglasii
- Heracleum lanatum
- Heracleum sphondylium
- Phonetic Spelling
- her-ah-KLEE-um MAKS-ih-mum
- This plant has low severity poison characteristics.
- See below
- This plant is an invasive species in North Carolina
- Description
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This plant is problematic and alternatives should be considered. Please see the suggestions in the left-hand column.
Cow parsnip is an herbaceous biennial or short-lived perennial wildflower in the Apiaceae (carrot) family native to North America and temperate Asia. It is the only member of the genus Heracleum that is native to North America. In North Carolina it is found in the western mountains. It inhabits marsh edges, streamsides, and damp open meadows.
The first year basal leaves are formed but the second year a 4-15 foot tall flowering stem emerges with a 6-8 inch compound umbel of many small white flowers. Its flowers attract a large diversity of pollinators.
This plant prefers silty or sandy loams in full sun to partial shade but will tolerate other soils if enough moisture is provided. They need moist conditions but not constantly wet ones. While they attract pollinators this plant is an aggressive grower that is insidiously weedy through self-seeding and it easily dominates landscapes out-competing native plants.
Insects, Diseases, Other Plant Problems: This plant is considered a federal noxious weed according to the Federal Noxious Weed Act of 1974 (7 U.S.C. 2802 ©). It is also considered a Class "A" North Carolina Noxious Weed. Do not get the sap from this plant on your skin or in your eyes and then be exposed to the sun as severe blistering and even blindness can occur. Wear gloves when handling this plant.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Heracleum
- Species:
- maximum
- Family:
- Apiaceae
- Uses (Ethnobotany):
- Native Americans used the hollow stems to make deer calls
- Life Cycle:
- Biennial
- Perennial
- Recommended Propagation Strategy:
- Seed
- Country Or Region Of Origin:
- North America, Asia
- Distribution:
- AK , AZ , CA , CO , CT , DE , GA , IA , ID , IL , IN , KS , KY , MA , MD , ME , MI , MN , MO , MT , NC , ND , NE , NH , NJ , NM , NV , NY , OH , OR , PA , RI , SD , TN , UT , VA , VT , WA , WI , WV , WY Canada: AB , BC , NB , NL , NS , ON , PE
- Wildlife Value:
- Larval host of Anise swallowtail butterfly. Flowers attract many different pollinators
- Play Value:
- Wildlife Food Source
- Wildlife Larval Host
- Edibility:
- Young stems can be peeled, cooked and eaten. Roots can be cooked and eaten like parsnip.
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Whole Plant Traits:
- Plant Type:
- Herbaceous Perennial
- Wildflower
- Habit/Form:
- Erect
- Growth Rate:
- Rapid
- Maintenance:
- High
- Texture:
- Fine
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Clay
- Loam (Silt)
- Sand
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Good Drainage
- Moist
- Occasionally Wet
- NC Region:
- Coastal
- Mountains
- Piedmont
- USDA Plant Hardiness Zone:
- 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a
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Fruit:
- Fruit Color:
- Brown/Copper
- Cream/Tan
- Green
- White
- Display/Harvest Time:
- Fall
- Fruit Type:
- Schizocarp
- Fruit Length:
- < 1 inch
- Fruit Description:
- 1/4 inch oval, flattened schizocarps are green with white margins. Mature to tan or brown and margins flatten into wings. They contain 2 seeds. Seeds are viable in the soil up to 15 years.
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Flowers:
- Flower Color:
- White
- Flower Inflorescence:
- Umbel
- Flower Value To Gardener:
- Showy
- Flower Bloom Time:
- Summer
- Flower Petals:
- 4-5 petals/rays
- Flower Size:
- < 1 inch
- Flower Description:
- 6-8 inches across flat compound umbrels of many small white flowers. Blooms June-July
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Leaves:
- Leaf Color:
- Green
- Leaf Value To Gardener:
- Showy
- Leaf Type:
- Compound (Pinnately , Bipinnately, Palmately)
- Leaf Arrangement:
- Alternate
- Leaf Shape:
- Obovate
- Orbicular
- Leaf Margin:
- Serrate
- Hairs Present:
- No
- Leaf Length:
- > 6 inches
- Leaf Width:
- 3-6 inches
- Leaf Description:
- The lower to middle stem leaves are compound with 3 leaflets. Leaflets are 4-12 inches long with 3-5 lobes and serrated margins. Upper surface is green to yellow-green and rough with the undersides being paler with hairs along the veins. The upper stem leaves are simple, 3-lobed, serrated margins and 4 inches long and wide.
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Stem:
- Stem Color:
- Green
- Purple/Lavender
- Stem Is Aromatic:
- No
- Stem Cross Section:
- Round
- Stem Form:
- Straight
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- The stem is grooved, hollow, and stout, green with purple splotches. White wooly hairs circle the stem at the base of the leaves. They have a strong pungent odor when crushed.
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Landscape:
- Attracts:
- Bees
- Butterflies
- Problems:
- Contact Dermatitis
- Invasive Species
- Problem for Cats
- Problem for Children
- Problem for Dogs
- Problem for Horses
