Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Asterids: Campanulids: Apiales
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Conium maculatum
FAMILY
Apiaceae
Go to FSUS key
Dig deeper at SERNEC, a consortium of southeastern herbaria.
Check out EDDMapS.org to see where this has been reported.
Poison-hemlock's leaves are large, cut fernlike, the outline triangular, the segments with narrow lobes. The somewhat similar Cicuta maculata has much broader leaflets that are not cut so deeply as to look "lacy". Read more at Vascular Plants of North Carolina.
All parts of the plant are highly toxic if ingested, causing respiratory failure in humans and other mammals, per Weakley's Flora (2022)
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Conium maculatum
FAMILY
Apiaceae
SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Conium maculatum
SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 140-24-001:
Conium maculatum FAMILY Apiaceae
SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)
Conium maculatum
COMMON NAME:
Poison-hemlock
To see larger pictures, click or hover over the thumbnails.
)
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913 pnd_coma2_001_lvd
)
USDA / Selected Weeds of the US. 1970 swus_page_281
)
JK Marlow jkm090405_092
April Walker County GA
)
JK Marlow jkm090405_094b
April Walker County GA
Stems hollow, spotted, per Vascular Flora of the Carolinas (Radford, Ahles, & Bell, 1968).
)
JK Marlow jkm090524_012
May Pickens County SC
Roadside ditch
Leaves broadly triangular, 3-4x pinnately compound, can be over 12" long, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).
)
JK Marlow jkm090524_014
May Pickens County SC
Roadside ditch
)
JK Marlow jkm090524_017
May Pickens County SC
Roadside ditch
)
JK Marlow jkm090524_037
May Pickens County SC
Roadside ditch
A coarse, taprooted biennial to 9' tall, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).
)
JK Marlow jkm090524_042
May Pickens County SC
Roadside ditch
)
JK Marlow jkm090524_057
May Pickens County SC
Roadside ditch
)
JK Marlow jkm090524_059
May Pickens County SC
Roadside ditch
)
JK Marlow jkm090524_063
May Pickens County SC
Roadside ditch
Tiny white flowers in umbels 1.5-2.5" wide, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).
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Richard and Teresa Ware rtw_conium_maculatum_19
May
)
Ron Lance rwl_conium_maculatum
June Jackson County NC
Big Ridge Preserve
)
Steve Dewey, Utah State University, Bugwood.org bug_1459207
Month Unknown
)
Joseph M. DiTomaso, University of California - Davis, Bugwood.org bug_5374190
Month Unknown
)
Joseph M. DiTomaso, University of California - Davis, Bugwood.org bug_5374191
Month Unknown
)
John M. Randall, The Nature Conservancy, Bugwood.org bug_5392073
Month Unknown
)
Bruce Ackley, The Ohio State University, Bugwood.org bug_5438055
Month Unknown
)
D. Walters and C. Southwick, Table Grape Weed Disseminule ID, USDA APHIS ITP, B bug_5458174
Month Unknown
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Conium maculatum
FAMILY
Apiaceae
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Conium maculatum
FAMILY
Apiaceae
SYNONYMOUS WITH
Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Conium maculatum
SYNONYMOUS WITH
VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 140-24-001:
Conium maculatum
FAMILY
Apiaceae
SYNONYMOUS WITH
Manual of the Southeastern Flora (Small, 1933, 1938)
Conium maculatum
2837
Forb
Biennial
Habitat: Ditches, roadsides, streambanks, pastures, disturbed areas, per Weakley's Flora
Non-native: Eurasia
Uncommon (rare in SC Coastal Plain) (rare in GA)
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.
This plant may be causing problems in natural areas outside its native range, according to authorities such as:
LEAVES:
Complexly compound, with 2+ levels of pinnate and/or ternate compoundness
Alternate
FLOWER:
Spring/Summer
White
Radially symmetrical
5-merous
Inferior ovary
Flowers in compound umbels
FRUIT:
Summer
Schizocarp of two mericarps
TO LEARN MORE about this plant, look it up in a good book!
- Guide to the Wildflowers of SC, 2nd ed. (McMillan, Porcher, Rayner, & White; 2022) p468
- Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007) p341
- Wildflowers of the Atlantic Southeast (Cotterman, Waitt, & Weakley, 2019) p147
- Wild Flowers of NC, 2nd edition (Justice, Bell, & Lindsey, 2005) p168
- Wildflowers of Tennessee (Carman, 2005) p175
- Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005) p212
- Wildflowers of the Southern Mountains (Smith, 1998) p115
- Wildflowers of the Sandhills Region (Sorrie, 2011) p242
If a search such as "Carex leptalea var. leptalea" doesn't deliver the results you want, try "Carex leptalea".
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