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Poison Hemlock Conium maculatum

Phonetic Spelling
KOH-nee-um mak-yoo-LAY-tum
This plant has high severity poison characteristics.
See below
Description

Poison hemlock is an erect biennial weed in the Apiaceae (carrot) family. It is found growing in disturbed areas, roadsides, along fences streambanks, or in ditches.

It starts growing emerging from the soil with a basal rosette of fine-textured ferny leaves in early spring, while it is usually a biennial growing for 2 years, in ideal locations it can be perennial.  Reaching a mature height of 6 to 9 feet tall poison hemlock grows in full sun to partial shade and moist soils.  It reproduces by seeds are dispersed by animals, machinery, and clothing and persist in the soil profile years making eradication difficult.

It has a white fleshy taproot with red spots that resembles a parsnip and hollow stems with small purple spots.  Showy white flowers look like umbrellas or like other members of the carrot family.  The leaves of poison hemlock resemble parlsey's leaves (Petroselinum crispum). The roots, leaves, and stems have a foul odor when crushed. 

Insects, Diseases, and Other Plant Problems: This plant is extremely poisonous to both humans and livestock.  Wear gloves when handling.

 

 

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#showy flowers#poisonous#white flowers#pink flowers#fine texture#weedy#lacy leaves#high maintenance#moist soil#fast growing#disturbed areas#malodorous#problem for cats#problem for dogs#problem for horses#roadside#contact dermatitis
 
Cultivars / Varieties:
Tags:
#showy flowers#poisonous#white flowers#pink flowers#fine texture#weedy#lacy leaves#high maintenance#moist soil#fast growing#disturbed areas#malodorous#problem for cats#problem for dogs#problem for horses#roadside#contact dermatitis
  • Attributes:
    Genus:
    Conium
    Species:
    maculatum
    Family:
    Apiaceae
    Life Cycle:
    Biennial
    Perennial
    Country Or Region Of Origin:
    Europe, Mediterranean
    Distribution:
    Naturalized in USA
    Dimensions:
    Height: 6 ft. 0 in. - 10 ft. 0 in.
    Width: 4 ft. 0 in. - 5 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Perennial
    Poisonous
    Weed
    Habit/Form:
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    High
    Texture:
    Fine
  • 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 Drainage:
    Moist
  • Fruit:
    Fruit Color:
    Brown/Copper
    Gray/Silver
    Green
    Fruit Description:
    Green ovoid to suborbicular compressed laterally and wavy ribbing on the surface containing several seeds. At maturity fruit turns gray-brown. The seeds resemble anise.
  • Flowers:
    Flower Color:
    Pink
    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:
    Small, white 5 petaled, in terminal umbrella-like clusters with one purple flower in the center of the cluster. Flowers appear late summer.
  • Leaves:
    Leaf Color:
    Green
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Shape:
    Deltoid
    Ovate
    Hairs Present:
    No
    Leaf Description:
    Large, 3-4 pinnately dissected, the leaflets broadly ovate to deltate very delicate and resemble parsley leaves with prominate veins on the underside. They clasp the stems at enlarged nodes.
  • Stem:
    Stem Color:
    Brown/Copper
    Green
    Purple/Lavender
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Buds:
    Smooth/Hairless
    Stem Cross Section:
    Round
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    Smooth, purple, brown, or red spots and fine regular lines, hollow stem foul odor when crushed.
  • Landscape:
    Problems:
    Contact Dermatitis
    Malodorous
    Poisonous to Humans
    Problem for Cats
    Problem for Dogs
    Problem for Horses
    Weedy
  • Poisonous to Humans:
    Poison Severity:
    High
    Poison Symptoms:
    HIGHLY TOXIC, MAY BE FATAL IF EATEN! Delivery by ingestion. Salivation, vomiting, diarrhea, muscular weakness, paralysis, nervousness, trembling, dilation of pupils, weak pulse, convulsions, coma.
    Poison Toxic Principle:
    Alkaloids coniine and others
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Bark
    Flowers
    Fruits
    Leaves
    Roots
    Sap/Juice
    Seeds
    Stems