|Apium graveolens var. rapaceum|
|A celeriac hypocotyl sliced in half, and with the greens removed|
Celeriac (Apium graveolens var. rapaceum), also called turnip-rooted celery or knob celery, is a variety of celery cultivated for its edible roots, hypocotyl, and shoots; these are sometimes collectively (but erroneously) called celery root.
Celeriac is a root vegetable with a bulbous hypocotyl. In the Mediterranean Basin and in Northern Europe, celeriac grows wild and is widely cultivated. It is also cultivated in North Africa, Siberia, Southwest Asia, and North America. In North America, the Diamant cultivar predominates. Celeriac originated in the Mediterranean Basin.
Culinary use 
Typically, celeriac is harvested when its hypocotyl is 10–14 cm in diameter. It is edible raw or cooked, and tastes similar to the stalks (the upper part of the stem) of common celery cultivars. Celeriac may be roasted, stewed, blanched, or mashed. Sliced celeriac occurs as an ingredient in soups, casseroles, and other savory dishes.
Unlike many root vegetables, celeriac contains little starch: 5–6% by weight. 
See also 
- "Growing Crops: Celery and Celeriac". Urban Organic Gardening. 17 June 2011. Retrieved 28 January 2012.
- Schuchert, Wolfgang. "Celeriac (Apium graveolens L. var. rapaceum)". Crop Exhibition. Max Planck Institute for Plant Breeding Research. Retrieved 28 January 2012.
- Chisholm, Hugh, ed. (1911). "Celery". Encyclopædia Britannica (11th ed.). Cambridge University Press. Retrieved 31 January 2012.
- "Celeriac (Apium graveolens rapaceum)". Desirable Vegetable Varieties, By Vegetable. The Owlcroft Company. Retrieved 28 January 2012.
- "Nutrient data for 11141, Celeriac, raw". USDA National Nutrient Database for Standard Reference. Retrieved 03 February 2012.