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Synonyms: Ruppiaceae Horan., nom. cons.; Zannichelliaceae Chevall., nom. cons.
Common name: Pondweed Family.
Number of genera 8. Number of species 90.
Angiosperm. Liliopsida.
Disseminule an intact or entire fruit.
Fruits
Pistil(s) simple; 1; 1-pistillate. Fruit pericarpium; multiple, or simple; berry (Groenlandica), or achene, or drupe (latter 2 of authors & also labelled subrupacous-achene, but not Spjut); achenetum (Potamogeton, Zannichellia), or drupetum (Ruppia & Spjut has 4 families: Amborellaceae, Menispermaceae, Rosaceae, Ruppiaceae = Potamogetonaceae); without persistent central column; not within accessory organ(s); 1-seeded; 1-seeded; (2–)4–5(–16)-carpellate; with carpels separate; with carpels not radiating at maturity; without sterile carpels; not sulcate; apex beaked, or not beaked; apex short beaked; indehiscent. Epicarp dull; durable; membranous; glabrous (without hairs); without armature; not smooth, or smooth; ridged (Ruppia with longitudinal crest); with wing(s), or without wing(s); 1-winged; with wing(s) lateral; without apical respiratory hole. Mesocarp present; fleshy; composed of 1 unified layer; without lactiform cavity system. Endocarp present, or absent; not separating from exocarp; hard (bony); not splitting into 1-seeded pyrenes; not smooth, or smooth; with warts, or ridges, or papillae; without operculum, or with operculum (Ruppia); without secretory cavities; without longitudinal ridges. Funiculus short; short without seed bearing hooks (retinacula); not persisting in fruit after seed shed.
Seeds
Aril absent. Seed oblong, or circular (more or less); in transection compressed; not bowl shaped; not nutlike; without winglike beak; without caudate appendage(s); at maturity with food reserves; with endosperm; without canavanine. Sarcotesta absent. Testa present; without markedly different marginal tissue; without fleshy or leathery layer over hard layer; loose; without crease or line separating cotyledons from hypocotyl-radicle; without notch along margin where cotyledons from hypocotyl-radicle tip approach each other; without glands; without bristles; glabrous; without wings; without collar; without operculum; colored; monochrome; membranous; not becoming mucilaginous when wetted; surrounding embryo. Endosperm development initially helobial and cellular (finally).
Embryo differentiated from food reserve; well developed; 1 per seed; completely filling testa (no food reserve); 1 times the length of food reserve; at one end of seed not extending into a depression or cup; axile and centric; linear; flatly coiled (circinate), or straight; with cotyledons gradually connected to hypocotyl-radicle; without coleoptile; without coleorhiza; without simmondsin; with cotyledons containing oils and starch; without stomata; not green; with 1 cotyledon. Cotyledons one and oblique and enclosing plumule; not modified into scutellum; not circinately coiled, or circinately coiled (Zannichellia). Hypocotyl-radicle well developed; not thickened.
Distribution
Cosmopolitan. New World, Old World. North America, Middle America, South America, Europe, Africa, Asia Major, Asia Minor, southeastern Asia, Australia, Oceania.
Notes
Haynes: Ruppia fruit dorsally rounded or with a prominent transversely ridges crest, outer layers decaying leaving operculate endocarp intact. Potamogeton fruit dorsally rounded or keeled, beaked. Zannichellia fruit drupe, membranous exocarp, fleshy mesocarp, endocarp stony and opening by two valves.
Weed information
1 or more USA state noxious weeds.
USA states and territories with listed noxious weeds: Alabama (AL), Connecticut (CT), Maine (ME), Massachusetts (MA), Minnesota (MN), New Hampshire (NH), Puerto Rico (PR), Vermont (VT), Wisconsin (WI).
USA state and territory noxious weeds: -- Potamogeton crispus L.: USA state noxious weed: ALª●, CTª, MAª, MEª, MNª, NHª, VTª, WIª. -- Potamogeton illinoensis Morong: USA state noxious weed: PRª. -- Potamogeton pectinatus L. (=Stuckenia pectinata (L.) Borner): USA state noxious weed: PRª. -- Potamogeton spp.: USA state noxious weed: PRª. -- Symbols: ªaquatic weed; ●terrestrial weed; °weed in seed. -- Last updated September 2008.
Listed seeds
ISTA listed seeds.
ISTA listed seeds: -- Potamogeton crispus L.w -- Symbols: aagricultural and vegetable seeds (Table 2A Part 1); ttree and shrub species (Table 2A Part 2); fflower, spice, herb, and medicinal seeds (Table 2A Part 3); wweed seeds. -- Last updated September 2008.
Accepted genera
Althenia F. Petit -- Groenlandia J. Gay -- Lepilaena J. Drumm. ex Harv. -- Potamogeton L. -- Pseudalthenia (Graebn.) Nakai -- Ruppia L. -- Stuckenia Börner -- Zannichellia L.
References specific to this family
Cronquist page 1064 (including 1066: Ruppiaceae & 1968: Zannichelliaceae). Haynes, R.R. 1978. The Potamogetonaceae in the southeastern United States. J. Arnold Arbor. 59:170–191; Durani, S. & A.M. Kak. 1988. Seed morphology of the genus Zannichellia (Zannichelliaceae). J. Econ. Taxon. Bot. 12:385–386; Tomlinson, P.B. & U. Posluszny. 1976. Generic limits in the Zannichelliaceae (sensu Dumortier). Taxon 25:273–279; Takaso, T. & F. Bowman. 1984. Ovule ontogeny and seed development in Potamogeton natans L. (Potamogetonaceae), with a note on the campylotropous ovule. Acta Bot. Neerl. 33:519–533.
General references
Cronquist, A. 1981. An integrated system of classification of flowering plants, 1,262 p. Columbia University Press, New York, Dahlgren, R.M.T., H.T. Clifford and P.F. Yeo. 1985. The families of the monocotyledons, 520 pp. Springer-Verlag, Berlin, Gaertner, J. 1788–1805. De fructibus et seminibus plantarum. The Author, Stuttgart, Goldberg, A. 1986 (dicots) and 1989 (monocots). Classification, evolution, and phylogeny of the familes of Dicotyledons. Smithsonian Contr. Bot. 58 for dicots (314 pp.) and 71 for monocots (74 pp.). [Goldberg's illustrations are reproduced from older publications and these should be consulted], Gunn, C.R. and C.A. Ritchie. 1988. Identification of disseminules listed in the Federal Noxious Weed Act. Techn. Bull. U.S.D.A. 1719:1–313, Gunn, C.R., J.H. Wiersema, C.A. Ritchie, and J.H. Kirkbride, Jr. 1992 and amendments. Families and genera of Spermatophytes recognized by the Agricultural Research Service. Techn. Bull. U.S.D.A. 1796:1–500, Haynes, R.R. and L.B. Holm-Nielsen. 1985. A generic treatment of Alismatidae in the neotropics with special reference to Brazil. Acta Amazonica, Supl. 15:153–193, Mabberley, D.J. 1987. The plant-book, 706 p. Cambridge University Press, Cambridge, Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.
Illustrations
Acceptable fruit and no seed illustration. Cronquist has no illustration of Ruppiaceae. Disseminule illustration(s): fruit, or embryo. Fruit illustration(s): Haynes & Holm-Nielsen, Haynes (1978), Dahlgren et al., NoxWeed, Karen. Embryo illustration(s): Dahlgren et al., Haynes & Holm-Nielsen, Gunn & Ritchie, Cronquist, Karen. Karen's plate number and taxon (taxa): 327: Potamogeton epihydrus Rafin. (A-B), from plate 328: Ruppia maritima L. (A-B).
• Fruit. 1 of 10. Potamogeton epihydrus Raf.: fruits. • Seed. 2 of 10. Potamogeton epihydrus Raf.: cross sectioned fruit with seeds. • Fruit. 3 of 10. Ruppia cirrhosa (Petagna) Grande: fruits. • Fruit. 4 of 10. Zannichellia palustris L.: fruits. • Seed. 5 of 10. Zannichellia palustris L.: seeds. • Embryo. 6 of 10. Althenia filiformis Petit: embryo. • Embryo. 7 of 10. Lepilaena cylindrocarpa (Walp.) Benth.: embryo. • Embryo. 8 of 10. Potamogeton epihydrus Raf.: embryo. • Embryo. 10 of 10. Zannichellia palustris L.: embryo.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘J.H. Kirkbride, Jr., C.R. Gunn, and M.J. Dallwitz. 2000 onwards. Family guide for fruits and seeds: descriptions, illustrations, identification, and information retrieval. Version: 12th April 2021. delta-intkey.com’.
