Description from Flora of China
Apium integrilobum Hayata.
Plants 15–150 cm, strongly fragrant. Basal leaves oblong to obovate, 7–18 × 3.5–8 cm, 3-lobed to 3-parted; ultimate segments subrhombic, 1.2–2.5 × 0.8–2.5 cm, crenate or serrate. Upper leaves short-petiolate; blade broad-triangular, usually 3-parted, ultimate segments obovate. Umbels 1.5–4 cm across, usually leaf-opposed; peduncles usually short, 4–15 mm, stout, rarely obsolete; rays 3–8(–16), 0.5–2.5 cm, slender; umbellules 7–25-flowered, 6–9 mm across; pedicels 1–1.5 mm. Fruit 1.3–1.5 × 1–2 mm. Fl. and fr. Apr–Jul.
This cosmopolitan species is cultivated as a vegetable (celery and celeriac) and is adventive in temperate regions worldwide. It has been cultivated since ancient times and features in the herbal medicinal traditions of many civilizations. All parts of the plant are used in traditional Chinese medicine as the dietary herb “qin” (also known as “han qin” and “qin cai”). There are several cultivated varieties; the culivated Chinese celery is thought to be close or identical to var. secalinum Alefeld.
Widely cultivated and adventive throughout China [?native to Asia and Europe; cultivated and adventive worldwide].