Sium sisarum, commonly known as skirret, is a perennial plant of the family Apiaceae sometimes grown as a root vegetable. The English name skirret is derived from the Middle English 'skirwhit' or 'skirwort', meaning 'white root'. In Scotland it is known as crummock. Its Danish name sukkerrod, Dutch name suikerwortel and German name "Zuckerwurzel" translate as 'sugar root'.
Skirret has a cluster of bright white, sweetish, somewhat aromatic roots, each approximately 15-20 cm in length. These are used as a vegetable in the same manner as the common salsify, black salsify and the parsnip.
The plant is of Chinese origin, but arrived in Europe by or before Roman times. It is presumed to be the siser mentioned by Pliny the Elder as a favourite of the Emperor Tiberius, though this may have also been a reference to a parsnip or carrot.
The twelfth-century Benedictine abbess Hildegard von Binge discussed the medicinal properties of skirret in her work Physica:
A 1390 manuscript The Forme of Cury used by King Richard II of England's master cooks included two recipes for fritters that included 'skyrwates'.