Name for the aquatic umbelliferous plants of the genus Sium, esp. S. latifolium; also applied to Helosciadium nodiflorum (sometimes classed as Sium nodiflorum).
1597. Gerarde, Herbal, II. xvii. 199. Great Water Parsnepe … is described to haue leaues of a pleasant sauour. Ibid., 200. [figure] Sium maius, Great water Parsnep.
1671. Salmon, Syn. Med., III. xxii. 432. Sium,… Water-parsnep.
1770. Ann. Reg., 118/1. Three children of a poor cottager in Ireland having eaten of the herb Daho or Water-parsnep, two of them died.
1785. Martyn, Lett. Bot., xvii. (1794), 229. The Creeping Water Parsnep, Sium nodiflorum Lin.
1861. S. Thomson, Wild Fl., III. (ed. 4), 234. The siums, or water-parsnips, are … not uncommon.
