Scientific NameConium maculatum
Other Common Names:
Biennial or perennial erect growing herb. A basal rosette of leaves forms the first year followed by a tall branched stem the second year.
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.
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.
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.
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.
upright and nonwoody
Thorns or Spines
Approximate Flower Diameter
Dominant Flower Color
shorter than leaf
Stem Cross Section
round or oval,
square or multi-edged