Poison Hemlock

Conium maculatum

Poison Hemlock

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Apiaceae
Genus:
Conium
Species:
Conium maculatum

Growth Characteristics

Life Cycle:
Biennial
Growth Habit:
Forb/herb
Height:
8-12 ft
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
may, aug
Bloom Colors:
white

Native Range

United States: Alabama, Arkansas, Arizona, California, Colorado, Connecticut, District of Columbia, Delaware, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Montana, North Carolina, North Dakota, Nebraska, New Hampshire, New Jersey, New Mexico, Nevada, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Vermont, Washington, Wisconsin, West Virginia, Wyoming, Canada: Alberta, British Columbia, New Brunswick, Nova Scotia, Ontario, Quebec, Saskatchewan

Host Plant for Caterpillars

hemlock moth (Agonopterix alstroemeriana), Anise Swallowtail (Papilio zelicaon), Black Swallowtail (Papilio polyxenes)

Reported Fauna Sightings

Bees: Yellow-faced bumble bee (Bombus vosnesenskii), Yellow-faced bumble bee (Bombus vosnesenskii) Butterflies:Acmon Blue (Plebejus acmon), Acmon Blue (Plebejus acmon), Arrowhead Blue (Glaucopsyche piasus), Arrowhead Blue (Glaucopsyche piasus), Behr's Hairstreak (Satyrium behrii), Behr's Hairstreak (Satyrium behrii), Brown Elfin (Callophrys augustinus), Brown Elfin (Callophrys augustinus), California Tortoiseshell (Nymphalis californica), California Tortoiseshell (Nymphalis californica), Chalcedon Checkerspot (Euphydryas chalcedona), Common Ringlet (North America) (Coenonympha california), Common Ringlet (North America) (Coenonympha california), Common Roadside-Skipper (Amblyscirtes vialis), Common Roadside-Skipper (Amblyscirtes vialis), Common Wood-Nymph (Cercyonis pegala), Common Wood-Nymph (Cercyonis pegala), Dreamy Duskywing (Erynnis icelus), Dreamy Duskywing (Erynnis icelus), Field Crescent (Phyciodes pulchella), Field Crescent (Phyciodes pulchella), (Pieris napi), (Pieris napi), Lorquin's Admiral (Limenitis lorquini), Lorquin's Admiral (Limenitis lorquini), Lustrous Copper (Lycaena cupreus), Lustrous Copper (Lycaena cupreus), Melissa Blue (Plebejus melissa), Melissa Blue (Plebejus melissa), Mourning Cloak (Nymphalis antiopa), Mylitta Crescent (Phyciodes mylitta), Mylitta Crescent (Phyciodes mylitta), Northern Checkerspot (Chlosyne palla), Northern Checkerspot (Chlosyne palla), Pale Swallowtail (Pterourus eurymedon), Spring Azure (Celastrina ladon), Spring Azure (Celastrina ladon), Square-dotted Blue (Euphilotes battoides), Thicket Hairstreak (Callophrys spinetorum), Thicket Hairstreak (Callophrys spinetorum), Western Tiger Swallowtail (Pterourus rutulus), 🛑Zerene Fritillary (Speyeria zerene), 🛑Zerene Fritillary (Speyeria zerene)

Soil Requirements

Soil Type:
rich, well-drained loamy soil
pH:
6.0 - 8.0 (slightly acidic to neutral)
Drainage:
tolerates poor drainage
Moisture:
consistently moist
Notes:
commonly found in disturbed areas and roadsides