This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
Gipsywort being a paludal plant is found in Preglacial beds in Norfolk and Suffolk; Interglacial, late Glacial beds, in Suffolk; and Neolithic beds. Its distribution lies in the Temperate regions in Europe, N. Africa, Siberia, W. Asia, as far east as India, N. America, Australia. It is thus a cosmopolitan species. In Great Britain it does not occur in Berwick, Haddington, Edinburgh, N. Perth, Forfar, N. Aberdeen, Banff, Dumbarton, N. Ebudes, Sutherland, Caithness, Northern Isles, or Brecon, Radnor, Montgomery, Merioneth, Wigtown, Peebles, Selkirk, Mull, W. Ross. From Ross it ranges to the S. coast. It is rare in Scotland, commoner in Ireland.
There is scarcely a ditch or wet place where one may not come across Gipsywort in the summer, for it is a common hygrophilous plant, frequenting the sides of streams, brooks, and rivers, as well as the still waters of ponds, pools, and lakes, along with Bur-reed, Bulrush, and reeds.
I he square, erect stem is more or less simple, with egg-shaped, coarsely toothed, veined leaves, opposite, acute, likened to a wolf's foot by Linnaeus, hence the first Greek name. The stem is roughly hairy and bears opposite branches. The flowers are small, white, in whorls, close, with a tubular, stiffly hairy calyx, with awl-shaped segments. The corolla is a cylindrical tube with a short limb, with 4 blunt, softly and loosely hairy segments. The nutlets equal the tube of the calyx, and are brown and polished. There are only 2 stamens. Gipsywort is from 2-3 ft. high. Flowers are to be found in July and August. The plant is a perennial propagated by division.