Hippuris vulgaris L.
Mare's tail.
Hippuridaceae, mares tail family.
Sp. Pl. 4.1753
Vegetative morphology. Plants perennial herbs; (4–)30–100(–150) cm high; aquatic, heterophyllous leaves in whorls of (2-)6–12(-18) with single unbranched stems that emerge above the water when flowering, more often growing submerged. Ground-level or under-ground stems horizontal (and semi-horizontal stems, rooting in soft substrates); rhizomatous (but rhizomes are rarely found on herbarium specimens); elongate, or compact. Aerial stems erect; not conspicuously jointed; glabrous. Leaves heterophyllous (particularly when plants grow in shallow water), or not heterophyllous (submerged plants); distributed along the stems; whorled (4–10 leaves per whorl); simple; existing for a single season or less. Petioles absent. Blades (2–)5–15 mm long; 0.5–2 mm wide. Blades herbaceous (submerged leaves), or succulent (emergent leaves); linear (to linear attenuate). Blades adaxial surface glabrous. Blades abaxial surface glabrous. Blade margins cut into linear divisions (submerged leaves), or not lobed (aerial leaves, a contrast with Myriophyllum).
Reproductive morphology. Plants bisexual (usually), or monoecious (occasionally female only). Flowering stems absent. Inflorescence spicate; axillary. Pedicels absent. Flowers small, less than 5 mm in diameter or length; zygomorphic (very reduced). Perianth absent. Flowers unisexual. Stamens 1 (arising from the top of the ovary). Gynoecia inferior. Carpels monomerous (pseudo-monomerous); 1. Styles present. Placentation apical. Ovules 1 (pendulous). Fruit fleshy; a nut; spherical; indehiscent. Fruit 1.8–2.2 mm long; 0.8–1.2 mm wide. Seeds 1; 1.8–2.2 mm long; brown.
Chromosome information. 2n = 32 (19 counts in Löve and Löve 1975). Juel (1911 northern Europe); Winge (1917 northern Europe); Sørensen and Westergaard in Löve and Löve (1948 Greenland); Löve and Löve (1956b Iceland, 1982a central Canada, 1982c eastern Canada); Jørgensen et al. (1958 Greenland); Sokolovskaya (1960a north eastern Asia; Sakhalin, 1963 north eastern Asia, Kamtch, 1970 north eastern Russia); Lövkvist in Weimarck (1963 Sweden); Sorsa (1963c Finland); Löve and Ritchie (1966 northern Canada); Zhukova (1966, 1968 northe eastern Asia, 1980 southern Chukotka); Johnson and Packer (1968 northwestern Alaska ); Taylor and Mulligan (1968 western Canada); Zhukova et al. (1973 northern and north eastern Asia, 1977a north eastern Asia); Packer and McPherson (1974 northern Alaska); Zhukova and Petrovsky (1976 western Chukotka); Krogulevich (1976 northern Siberia); Engelskjøn (1979 northern Norway); Yurtsev and Zhukova (1982 northern Siberia); Lövkvist & Hultgård (1999 southern Sweden). Numerous more southern counts. Supposed basic chromosome number of family 4x.
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada, United States, Eurasia. Arctic Islands: Baffin, Devon, Ellesmere, Banks, Victoria, Somerset, Southampton, and Coats (Boothia Peninsula).
Ecology and habitat. Substrates: aquatic (in water to 1 m deep).
Notes. With a bit of imagination the tops of the plant sticking up
above the water look like a tail of a horse, or more likely a donkey (Burt,
2000. Ducks feed on mare's tail, and wild-food enthusiasts use it a pot-herb, or
cook it in chowders, but it has been described as tasting very green (Schofield
1989). The Inupiat and Yupik of Alaska cook it in water with seal oil and add
seal blood to make a soup. The Inuit of the Central Arctic do not use it (Burt
2000).
Glooschenko and Martini (1987) in a study made of the vegetation of
four river-influenced coastal marshes located between the Moose River and
Harricanaw River in southern James Bay, found six major grouping of species.
These included 1. a salt marsh dominated by Puccinellia phryganodes,
P. lucida, Hippuris tetraphylla, and Scirpus maritimus 2.
saline ponds with Senecio congestus, 3. a saline/brackish meadow marsh
with Carex paleacea, 4. an intertidal estuarine marsh with Eleocharis
palustris, 5. freshwater ponds with Potamogeton filiformis, and 6. a
freshwater marsh/fen. Major environmental factors controlling the distribution
of these groups include substrate salinity, river flow patterns, storm surges
and tidal range. These marshes are unique in species composition in James
Bay.
.
Illustrations. • Hippuris vulgaris. Close-up of stem and flowers. Note about eight narrow, acute leaves in each whorl. Norway: Troms, Ibestand, Fugleberg. 09.07.1978. Photographed by R.Elven.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
