Includes the common herbs anise, carrot, celery, coriander, dill, fennel, parsley, and parsnip, as well as the highly toxic hemlocks. Sium suave var. Stems often furrowed.
Flowers usually compound, almost always concentrated in flat-topped umbels.
Flowers have 5 petals, usually uneven, and 5 stamens. Seeds and fruit form below where the petals and stamen originate. Some part of the plant usually has a strong aroma, due primarily to various oils produced by the plant. Leaves alternate, oblong to ovate in outline, divided into 11-15 leaflets. Leaves under water divided into thread-like or linear segments.