Ageratina altissima
Common Name(s):
Previously known as:
- Eupatorium rugosum
- Phonetic Spelling
- ah-jeh-rah-TEE-na all-TIS-see-mah
- This plant has high severity poison characteristics.
- See below
- Description
-
White Snakeroot is a herbaceous perennial in the aster family (Asteraceae) The plant is native to woodland areas in the Eastern United States and typically occurs in rich or rocky woods, thickets, wood margins, and rocky areas. The Genus name is Greek meaning 'un-aging', referring to the flowers keeping their color for a long time. The species name means 'tallest' as it is the tallest in the Genus. Native Americans used extract from the roots as a remedy for snakebite, hence the common name.
White Snakeroot is easily grown in average, moist well-drained soils in full sun to partial shade. In the southeast, it will appreciate some afternoon shade. It will grow 2-5 feet tall and 2-4 feet wide. This plant can spread by rhizomes or reseeding. Deadhead spent flower heads to avoid unwanted self-seeding.
Early settlers who drank milk from cows that fed on this plant often developed the disease called milk sickness and may have been the cause of death of Nancy Hanks Lincoln, mother of Abraham Lincoln. See information below for toxicity.
Use in the border of cottage gardens, woodland gardens, and naturalized areas.
Diseases, Insects and Other Plant Problems: Susceptible to leaf miners and flea beetles may attack the foliage.
- See this plant in the following landscape:
- Cultivars / Varieties:
-
- 'Chocolate'
Dark tinted leaves. Best color occurs if it gets some sun.
- 'Chocolate'
- 'Chocolate'
- Tags:
- Cultivars / Varieties:
-
- 'Chocolate'
Dark tinted leaves. Best color occurs if it gets some sun.
- 'Chocolate'
- 'Chocolate'
- Tags:
-
-
Attributes:
- Genus:
- Ageratina
- Species:
- altissima
- Family:
- Asteraceae (Compositae) - Aster or Sunflower Family
- Life Cycle:
- Perennial
- Recommended Propagation Strategy:
- Division
- Seed
- Country Or Region Of Origin:
- Native to woodlands in Eastern United States
- Distribution:
- AL , AR , CT , DC , DE , FL , GA , IA , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , NC , ND , NE , NH , NJ , NY , OH , OK , PA , RI , SC , SD , TN , TX , VA , VT , WI , WV Canada: NB , NS , ON , SK
- Wildlife Value:
- Flowers are attractive to butterflies, especially smaller species, and other pollinators, including leaf-cutting bees. Songbirds eat the seeds.
- Edibility:
- Toxic
- Dimensions:
- Height: 2 ft. 0 in. - 5 ft. 0 in.
- Width: 2 ft. 0 in. - 4 ft. 0 in.
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-
Whole Plant Traits:
- Plant Type:
- Herbaceous Perennial
- Native Plant
- Poisonous
- Wildflower
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Ascending
- Clumping
- Erect
- Growth Rate:
- Medium
- Maintenance:
- Low
- Texture:
- Medium
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-
Cultural Conditions:
- Light:
- Deep shade (Less than 2 hours to no direct sunlight)
- 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)
- Soil pH:
- Alkaline (>8.0)
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
- Occasionally Dry
- Available Space To Plant:
- 3 feet-6 feet
- NC Region:
- Coastal
- Mountains
- Piedmont
- USDA Plant Hardiness Zone:
- 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
-
-
Fruit:
- Fruit Color:
- Black
- Display/Harvest Time:
- Fall
- Fruit Type:
- Achene
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- The fruit is often referred to as an achene but is actually a cypsela. The seeds are small, oblong, ribbed and black with a tuft of white hair. They are distributed by the wind.
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-
Flowers:
- Flower Color:
- White
- Flower Inflorescence:
- Corymb
- Flower Value To Gardener:
- Fragrant
- Long Bloom Season
- Showy
- Flower Bloom Time:
- Fall
- Summer
- Flower Shape:
- Tubular
- Flower Size:
- < 1 inch
- Flower Description:
- Blooms on a terminal flat-topped corymb in late summer to fall. Each flower head is about 2-6 inches across and contains many 5-lobed, tubular disk flowers. There are no ray florets. They are densely packed creating a showy display.
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-
Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Green
- Leaf Feel:
- Prickly
- Leaf Type:
- Simple
- Leaf Arrangement:
- Opposite
- Leaf Shape:
- Cordate
- Lanceolate
- Ovate
- Leaf Margin:
- Crenate
- Serrate
- Hairs Present:
- No
- Leaf Length:
- 3-6 inches
- Leaf Description:
- Green leaves are up to 5 inches long and 3.5 inches across. The larger lower leaves are cordate to cordate-ovate and have more promenade veins. The smaller upper leaves are lanceolate. All leaves are hairless and have serrate to crenate margins.
-
-
Stem:
- Stem Color:
- Brown/Copper
- Green
- Stem Is Aromatic:
- No
- Stem Form:
- Straight
- Stem Surface:
- Smooth (glabrous)
- Stem Description:
- The light green to tan stems are terete and mostly hairless.
-
-
Landscape:
- Landscape Location:
- Woodland
- Landscape Theme:
- Butterfly Garden
- Native Garden
- Pollinator Garden
- Design Feature:
- Border
- Attracts:
- Butterflies
- Pollinators
- Songbirds
- Resistance To Challenges:
- Deer
- Problems:
- Poisonous to Humans
- Problem for Horses
-
-
Poisonous to Humans:
- Poison Severity:
- High
- Poison Symptoms:
- The plant is highly toxic and may be fatal if eaten. Toxicity is characterized by weakness, nausea, abdominal pain, vomiting, delirium, cardiac damage, prostration and eventually, coma.
- Poison Toxic Principle:
- Tremetone, a ketone, and glycosides
- Causes Contact Dermatitis:
- No
- Poison Part:
- Flowers
- Leaves
- Roots
- Sap/Juice
- Seeds
- Stems
