oHDiai.] HIPPURIS. 3 



GENUS II. HIPPU'RIS. Mare's Tail. 

 Nat. Ord. HALOKA'GEJE. 



GEN. CHAK. Perianth single, crowning the gerraen with a very slight 

 border. Seed one, inclosed in a small oval, hard, and shining 

 pericarp (nut). Named from hippos, a mare, and oura, a tail. 

 It was the opinion of the late Mr. Curtis, that the Hippuris of 

 Linnaeus was identical with a plant mentioned by Dioscorides 

 under a different name, and arranged by his commentator Matthi- 

 olus with our Polygamun aviculare and Herniaria : " succeeding 

 botanists," he says, " imagining from the growth of its leaves, or 

 from its producing seed, that it had better pretensions to be ranked 

 with the Equisetum, absurdly enough called it Canda equina. 

 fiemina, to which Mr. Hudson could not well avoid giving the 

 English name of Mare's-tail." 

 1. H. vulya'ris, (Fig. 3.) common Mare's Tail. Leaves linear, six to 



ten in a whorl. 



English Botany, t. 763. English Flora, vol. i. p. 3. Lindley, Sy- 

 nopsis, p. 110. Hooker, British Flora, vol. i. p. 2. 



Root jointed, the fibres whorled at each articulation. Stem undivided, 

 erect, shining, with a tough woody column passing through its centre. 

 Leaves about eight in a whorl, narrow, smooth, with a callous point, 

 spreading, about an inch in length. Flower small, attached to the stem 

 at the base of the upper leaves, never alternate ; superior to thegermen, 

 and bearing within its slight border a stamen and tapering thread-like 

 style : the former frequently absent in the lower part of the stem. 

 Filament at first short, afterwards nearly the length of the style. An- 

 ther when young of two large reddish lobes, with the style passing 

 between them. Germen oval, inferior. Seed single. 



The short stems remaining under water are thickly set with longer 

 and thinner leaves than those on the flowering stem, and generally ten 

 in a. whorl : the whorls frequently less than the eighth of an inch apart, 

 forming dense brush-like tufts. Dr. Hooker finds this plant at Sur- 

 lingham, Norfolk, two or three feet long, with the leaves excessively 

 crowded, three and even four inches in length, pellucid, with an opaque 

 nerve, their points not callous ; the whole plant submerged, and con- 

 sequently barren ; and at Ben-y-gloe, in Scotland, at a considerable 

 elevation above the sea, the opposite extreme of this, scarcely four inches 

 high. 



Habitat. Ditches, lakes, and slow streams; frequent in England, 

 in gravelly soil ; not so common in Scotland. 

 Perennial ; flowering June and July. 



It possesses slightly astringent qualities, and is sometimes used by 

 the country people as a tea in a relaxed state of the bowels, Sec. ; but 

 its virtues are so slight as to render it unworthy attention. 



