Conium

By far the more familiar species is Conium maculatum (Hemlock or Poison Hemlock). It is a herbaceous biennial plant that grows between 1.5–2.5 metres (5–8 ft) tall, with a smooth green stem, usually spotted or streaked with red or purple on the lower half of the stem. The leaves are finely divided and lacy, overall triangular in shape, up to 50 centimetres (20 in) long and 40 centimetres (16 in) broad. The flowers are small, white, clustered in umbels up to 10–15 centimetres (4–6 in) across. When crushed, the leaves and root emit a rank, unpleasant odour often compared to that of parsnips.