[5] Cow parsley is an upright herbaceous (non-woody) perennial, growing to 60–170 centimetres (24–67 inches) tall.

The stems are hollow, striate (striped with parallel, longitudinal lines), furrowed, and green in colour with flushes of purple, with a diameter up to 1.5 cm (0.59 in).

[8] There are downy oval bractioles with red pointy tips on the umblets, arranged on 4–10 rays 1.5–3 cm long.

Each flower has 5 white petals, 2 stamens and 2 styles with an enlarged base forming a swelling at the apex of the ovary (stylopodium).

It is a particularly common sight by the roadside and with its frothy early-flowering white blooms is regarded as the most important springtime landscape wildflower in Britain.

Cow parsley's ability to spread rapidly by means of rhizomes and to produce large quantities of seeds in a single growing season has made it an invasive species in many areas of the United States.

Because the plant's flavour is considered unremarkable and the risk is great, foraging cow parsley in the wild is usually strongly discouraged.