Apium graveolens is a marshland plant that has been cultivated as a vegetable since antiquity. Celery has a long fibrous stalk tapering into leaves. Depending on location and cultivar, either its stalks, leaves, or hypocotyl are eaten and used in cooking. Celery seed is also used as a spice and its extracts have been used in herbal medicine.
Celery leaves are pinnate to bipinnate with rhombic leaflets 3–6 cm (1.2–2.4 in) long and 2–4 cm (0.79–1.57 in) broad. The flowers are creamy-white, 2–3 mm (0.079–0.118 in) in diameter, and are produced in dense compound umbels. The seeds are broad ovoid to globose, 1.5–2 mm (0.059–0.079 in) long and wide. Modern cultivars have been selected for solid petioles, leaf stalks. A celery stalk readily separates into "strings" which are bundles of angular collenchyma cells exterior to the vascular bundles.