# poison hemlock (*Conium maculatum*) Poison hemlock is a tall plant with pretty white flowers that can be found in some fields and along roadsides. It is very important to remember that this plant is not safe to touch or eat! - **Category:** [Plants](https://www.snappit.app/explore/categories/plant) - **Rarity:** Rare - **Danger:** 5/5 · Extreme - **Snaps:** 53 - **Habitat:** Wetlands ![poison hemlock](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Conium_maculatum_Cresswell_01.jpg&width=800) Photo: MPF, CC BY-SA 3.0 · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Conium_maculatum_Cresswell_01.jpg) ## Appearance The poison hemlock has hollow stems marked with distinctive purple blotches, and finely divided, fern-like leaves. Its small white flowers grow in flat-topped clusters resembling tiny umbrellas. ## Taxonomy - **Kingdom:** Plantae - **Phylum:** Tracheophyta - **Class:** Magnoliopsida - **Order:** Apiales - **Family:** Apiaceae - **Genus:** Conium ## Interesting facts - Even touching poison hemlock can cause a rash or skin irritation for some sensitive people. - Its scientific name, Conium, means “whirl” or “dizzy” in Greek, describing its effect. - Socrates, a famous ancient Greek, was condemned to die by drinking poison hemlock. - This plant is often mistaken for edible wild carrots or parsley, which is very dangerous! ## Special abilities - **Toxic Shield:** Poison hemlock produces potent alkaloids, helping it defend against almost all hungry animals that try to eat it. - **Quick Colonizer:** Poison hemlock can rapidly grow and spread in disturbed soils, helping it quickly outcompete native plants for space. - **Seed Shower:** Poison hemlock produces thousands of tiny seeds per plant, ensuring its successful reproduction and wide dispersal. ## Measurements & details - **Height:** 100-300 cm - **Spread:** 50-100 cm - **Flower Size:** 0.2-0.5 cm - **Bloom Season:** Late spring to summer - **Edible:** No - **Toxicity:** Deadly - **Lifecycle:** Biennial - **Pollination Method:** Insect ## Ecological connections - **Pollinates:** European honey bee (*Apis mellifera*) — Visits flowers, but nectar can be toxic. - **Pollinates:** house fly (*Musca domestica*) — One of many generalist insect pollinators. - **Eats:** willow-carrot aphid (*Cavariella aegopodii*) — Specialized aphid feeds on its sap. ## Traits - [Spotted](https://www.snappit.app/explore/traits/spotted): Marked with spots or patches of a different color. - [Flowering](https://www.snappit.app/explore/traits/flowering): Flowering plants are any plants that produce flowers as part of their reproductive cycle. - [Biennial](https://www.snappit.app/explore/traits/biennial): Biennial plants complete their life cycle over two growing seasons, typically forming foliage in the first year and flowering/seeding in the second. - [Ancient Lineage](https://www.snappit.app/explore/traits/ancient-lineage): This trait signifies organisms belonging to a very old evolutionary group with ancestors dating back millions of years. - [Wetland](https://www.snappit.app/explore/traits/wetland): This habitat trait identifies species found in wetlands, which are areas of land saturated with water, either permanently or seasonally, including marshes, swamps, and bogs. - [Toxic](https://www.snappit.app/explore/traits/toxic): Toxic organisms contain substances that are poisonous and can cause adverse effects upon exposure. - [Poisonous](https://www.snappit.app/explore/traits/poisonous): Poisonous organisms produce toxins that can cause harm when ingested, inhaled, or absorbed through contact. ## Collections - [Plants](https://www.snappit.app/explore/collections/plants) ## Safety **Danger:** 5/5 · Extreme Never touch or eat any part of the poison hemlock plant. Always ask an adult if you're unsure about a plant. ## Frequently Asked Questions ### How to identify poison hemlock? Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details. ### How tall is poison hemlock? 100-300 cm ### How wide does poison hemlock spread? 50-100 cm ### How big are the flowers on poison hemlock? 0.2-0.5 cm ### When does poison hemlock bloom? Late spring to summer ### Is poison hemlock edible? No ### Is poison hemlock toxic? Deadly ### What is poison hemlock's lifecycle? Biennial ## Where to spot - [Arastradero Preserve](https://www.snappit.app/guides/places/arastradero-preserve) — California, US · Nature Reserve - [Bishop Hill Colony](https://www.snappit.app/guides/places/bishop-hill-colony) — Illinois, US · Historic District - [Blackhand Gorge State Nature Preserve](https://www.snappit.app/guides/places/blackhand-gorge-state-nature-preserve) — Ohio, US · Nature Reserve - [Cedarville State Forest](https://www.snappit.app/guides/places/cedarville-state-forest) — Maryland, US · Forest - [Crystal Cove Historic District](https://www.snappit.app/guides/places/crystal-cove-historic-district) — California, US · Historic District - [Dinosaur Ridge](https://www.snappit.app/guides/places/dinosaur-ridge) — Colorado, US · Natural Landmark [View all places to see poison hemlock](https://www.snappit.app/guides/where-to-see/poison-hemlock) ## More Plants - [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*) - [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*) - [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*) - [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*) --- Source: [Poison Hemlock: Facts & Places to See — Snappit](https://www.snappit.app/explore/poison-hemlock)