poison hemlock

Conium maculatum

Member of carrot family (family Apiaceae)
dicots (class Magnoliopsida)
white in flowering plants

There are no other wild species of this genus in California.

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• leaf is large, 2–3-pinnately compound, with ultimate leaflets that are divided deeply
• stem has purple stripes or splotches (sometimes called the “blood of Socrates”)

The hemlock conifer (a.k.a. Tsuga), a North American native, is named after the poison hemlock for unclear reasons, possibly because the crushed foliage is perceived to smell similarly.

Toxicity of deadly hemlock; hemlock; hemlock, poison; hemlock, spotted; poison hemlock; poison parsley (Conium maculatum):
4 – Ingestion of these plants, especially in large amounts, is expected to cause serious effects to the heart, liver, kidneys or brain. If ingested in any amount, call the poison center immediately.

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Chris’s observations: 54 (42 are research grade)

Locations:

• Almaden Quicksilver CP: 6
• Russian Ridge OSP: 4
• Santa Teresa CP: 4
• Butano SP: 3
• Calero CP: 3
• Coyote Hills RP: 3
• Murray Ranch SP: 3
• La Honda Creek OSP: 2
• Lake Chabot RP: 2
• Purisima Creek Redwoods OSP: 2
• Sunol Wilderness RP: 2
• Sweeney Ridge National Recreation Area: 2
• Waterdog Lake & Open Space: 2
• Alum Rock Park, San Jose
• Andrew Molera SP
• Bear Creek Redwoods OSP
• Coal Creek OSP
• Dimond Canyon Trail, Oakland
• Dr. Aurelia Reinhardt Redwood RP
• Ed R. Levin CP
• Garin RP
• Garrapata SP
• Huckleberry Botanic RP
• Joseph D. Grant CP
• San Bruno Mountain State & County Park
• San Pedro Valley CP
• Sierra Vista OSP
• Skyline Ridge OSP
• Stevens Creek CP

Months:

• Feb.: 3
• Mar.: 6
• Apr.: 6
• May: 7
• Jun.: 13
• Jul.: 9
• Aug.: 6
• Sep.: 1
• Oct.: 0
• Nov.: 2
• Dec.: 1

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Not all sites include this taxon:

• Conium maculatum → iNaturalist – Calflora – CalPhotos – Jepson eFlora
• not yet listed → FNA

Bay Area species: iNaturalist – Calflora