Apium is a genus of about 12 species of flowering plants in the family Apiaceae (the carrot family), and holds the distinction of being the type genus of both that family and the order Apiales. Its type species is Apium graveolens, the wild ancestor of the familiar vegetables celery, celeriac, and leaf celery.
The genus has a strikingly disjunct global distribution. A single species, Apium graveolens, occurs in the temperate Northern Hemisphere across the Western Palaearctic — Europe, western Asia, and north Africa — while the remaining species are confined to the temperate Southern Hemisphere, including southern Africa, southern South America, Australia, and New Zealand.
Plants in the genus are prostrate to medium-tall annual, biennial, or perennial herbs, reaching up to about 1 m in height. They typically grow in wet soil, frequently in marshes and salt marshes. The leaves are pinnate to bipinnate and the flowers are small and white, arranged in the compound umbels characteristic of the Apiaceae. Several species are edible; beyond the cultivated forms of A. graveolens, Apium prostratum (sea celery) is native across Australia, New Zealand, southern Africa, and southern South America.
Etymology
The name Apium is the classical Latin word for celery (or parsley), used in ancient Roman texts. The genus takes its name from its most familiar member, Apium graveolens (wild celery), which has been cultivated since antiquity.
Distribution
Apium has a highly disjunct distribution: Apium graveolens occurs in the Western Palaearctic (Europe, western Asia, and north Africa), while the other species are restricted to the temperate Southern Hemisphere — southern South America, southern Africa, Australia, and New Zealand. Many species favour wet habitats such as marshes and salt marshes.
Ecology
Apium species, including garden celery, serve as larval host plants for several Lepidoptera, including the angle shades, common swift, Hypercompe icasia, the nutmeg, setaceous Hebrew character, and turnip moth.
Cultural Uses
Apium graveolens, the wild ancestor of celery, has been cultivated for food since antiquity. Its domesticated forms — celery (stalk), celeriac (root), and leaf celery — are economically important vegetables worldwide. Apium prostratum (sea celery) has historically been used as a food plant in Australia and New Zealand.
Taxonomy Notes
Apium is the type genus of the family Apiaceae and the order Apiales. Several species formerly placed in Apium have been transferred to related genera: Helosciadium (e.g., Apium nodiflorum → Helosciadium nodiflorum, fool's-water-cress; Apium inundatum → Helosciadium inundatum; Apium repens → Helosciadium repens) and Cyclospermum (e.g., Apium leptophyllum → Cyclospermum leptophyllum). The genus currently comprises approximately 12 accepted species as circumscribed by Plants of the World Online.
