Conium maculatum L.


Conium maculatum, Poison-Hemlock is a biennial herbaceous plant in the carrot family (Apiaceae) that grows 3-8 ft. (0.9-2.4 m) tall. Stems are stout, hollow, ridged, and purple-spotted. C. maculatum has a thick, white taproot that may easily be mistaken for wild parsnips. All plant parts are poisonous; however, the seeds contain the highest concentration of poison. C. maculatum is native to Africa, temperate and tropical Asia and Europe.
Leaves are shiny green, 3-4 times pinnately compound, and clasp the stem at the swollen nodes. Crushed foliage and roots have a disagreeable, parsnip-like odor.
Flowers are small, white, and held in umbels about 3 in. (7.6 cm) across (appearing in early summer).
C. maculatum reproduces from seed. Fruits are ridged and flattened, and each fruit holds two seeds.
Ecological Threat
C. maculatum contains highly poisonous alkaloids toxic to mammals. Human deaths have occurred from harvesting and consuming the roots as wild carrots or parsnips. C. maculatum quickly colonizes disturbed habitats such as roadsides, old fields, fencerows and ditches. In natural areas it can displace native plant species and prefers riparian habitats. Many U.S states have listed C. maculatum as a noxious weed.


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EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Rosidae
Order: Apiales
Family: Apiaceae
Genus: Conium
Subject: Conium maculatum L.

Synonyms and Other Names

Other Common Names:
poison hemlock, deadly hemlock, poison parsley


Plants - Forbs/Herbs