The famous incident of Socrates' death in Athens in 329 BC occurred when he was given the juice of poison hemlock to drink. Look closely at the stem of any plant you may suspect of being poison hemlock. These blotches and streaks on a green hollow hairless stem, and the mottled purple spots, are definite identifiers of the plant. The finely divided leaves, fern-like, resemble Queen Anne's lace. Flowers are lacy and white, appearing from late May to August.
Poison hemlock is a biennial.
It grows from seeds. During the first year, it produces a rosette of fern-like leaves close to the ground. The second season it bolts to form the tall, erect, flowering stems which can be from 4 to 8 feet tall. The white flowers develop into green, ridged seed capsules which turn brown when the seeds mature. Poison hemlock must be removed.