Apium

A cool-season root vegetable in the carrot family (Apiaceae) grown for its swollen, edible, brown, turnip-like root, which tastes like celery with an additional turnip-like flavoring. Biennial by nature, it is grown as an annual: in its first season it forms a basal rosette of aromatic, pinnately divided leaves above the enlarging root, and only in a second year would it send up a summer bloom of off-white flowers in umbels. Missouri Botanical Garden PlantFinder describes a plant 2-3 feet tall and 1-1.5 feet wide that wants full sun, rich moist well-drained soil, and consistent water. It dislikes summer heat and humidity, growing best between 60-75 degrees F, and the root is ready to harvest after 3-4 months.

A cool-season biennial vegetable in the carrot family (Apiaceae), grown as an annual for its crisp, edible ribbed leaf stalks. Apium graveolens is native to temperate Mediterranean Europe, Asia, and Africa — not North America. It demands rich, consistently moist soil and steady cool temperatures (60-75°F); heat and drought turn the stalks stringy and bitter, which is why it is one of the more finicky garden vegetables.