Scientific Name: Conium maculatum

Common Name: poison hemlock

Other Common Names: cigue maculee, cigue tachetee, deadly hemlock, poison hemlock, poison parsely

Habit: Biennial or perennial erect growing herb. A basal rosette of leaves forms the first year followed by a tall branched stem the second year.

Leaves: Alternate and basal, triangular leaves that are 20-40 cm long and deeply lobed (almost like segments of the leaf). Leaflets are oval to oblong and hairless, with toothed margins. Petioles and stem are often spotted with purple. Lower leaves have a sheath that surrounds the stem. They are innately a compound.

Identifying Characteristics: There are distinctive purple spots located on the stem of poison-hemlock. It has a taproot.

Flower Seed Head: Small white flowers are formed in umbrella like clusters that are around 2 inches wide. Individual flowers are around 2-4 mm wide.

Seed Fruit: Fruit is a schizocarp containing two seeds. After maturity, the two sides break apart, and each half is rounded on one side and flat on the other with pale brown wavy ribs.

Where Found: It is common on roadsides and unmanaged areas, such as fence rows. It will infest areas where it is unprotected such as the center of a pasture. It does not tolerate mowing well.

  • Life cycle: biennial

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Apiaceae

  • Leaf arrangement: alternate; rosette

  • Leaf shape: triangle

  • Ochrea: Present; Not Present

  • Leaf margin: serrated; lobed

  • Stem hairs: no hairs

  • Flower color: white

  • Growth habit: upright and nonwoody

  • Stem: round or oval; square or multi-edged

  • Leaf structure: pinnate

  • Leaf hairs: no hairs

  • Flower diameter: pencil

  • Flower symmetry: radial symetery

  • Root structure: taproot

  • Leaf stalk: shorter than leaf