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Tremetol Ageratina altissima

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'
Tags:
#showy flowers#deciduous#poisonous#NC native#native garden#native wildflower#food source fall#food source herbage#food source nectar#food source pollen#bird friendly#food source hard mast fruit#butterfly friendly#FACU Piedmont Mountains#Coastal FACU#problem for horses#Audubon#perennial#wildflower#wildlife friendly
 
Cultivars / Varieties:
  • 'Chocolate'
    Dark tinted leaves. Best color occurs if it gets some sun.
'Chocolate'
Tags:
#showy flowers#deciduous#poisonous#NC native#native garden#native wildflower#food source fall#food source herbage#food source nectar#food source pollen#bird friendly#food source hard mast fruit#butterfly friendly#FACU Piedmont Mountains#Coastal FACU#problem for horses#Audubon#perennial#wildflower#wildlife friendly
  • 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.
  • 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
  • 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.
  • 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.
  • 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