Compilation
Ceratophyllum demersum

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Name

Identification
Ceratophyllum demersum L. [family CERATOPHYLLACEAE ] (stored under name);
Related name
  • Ranunculus pueblensis
  • Ceratophyllum missionis
  • Ceratophyllum cristatum
  • Ceratophyllum muricatum
  • Ceratophyllum demersum
  • Ranunculus trichophyllus
  • Ceratophyllum submersum
  • Ceratophyllum oxyacanthum
Common name
  • hornwort, Flora of North America Vol. 3
  • cornifle échinée, Flora of North America Vol. 3
  • Coontail, Flora of North America Vol. 3
  • Hornwort, Flora of North America Vol. 3
  • cornifle nageante, Flora of North America Vol. 3

Flora

Entry for Ceratophyllum demersum Linnaeus [family CERATOPHYLLACEAE]
Herbarium
Flora of North America (FNA)
Collection
Flora of North America
Resource Type
Reference Sources
Entry From
Flora of North America, Vol 3,
Names
Ceratophyllum demersum Linnaeus [family CERATOPHYLLACEAE], Sp. Pl., 2: 992. 1753
Ceratophyllum apiculatum Chamisso [family CERATOPHYLLACEAE]
Information
Stems to 3 m; apical leaf whorls densely crowded. Leaves bright green, coarse-textured. Leaf blade simple or forked into 2-4(-5) ultimate segments (forking of largest leaves 1st or 2d order, rarely 3d order), segments not inflated, mature leaf whorls 1.5-6 cm diam., marginal denticles conspicuous, usually strongly raised on broad base of green tissue; 1st leaves of plumule simple. Achene dark green or reddish brown, body (excluding spines) 3.5-6 × 2-4 × 1-2.5 mm, basal spines or tubercles 2 (rarely absent), straight or curved, 0.1-12 mm, spine bases occasionally inconspicuously webbed, marginal spines absent, terminal spine straight, 0.5-14 mm, margins wingless. 2n = 24, 38, 40, 48.
Phenology
Flowering spring-late fall
Altitude range
0-1700 m
Distribution
worldwide.USA Ala.USA AlaskaUSA Ariz.USA Ark.USA Calif.USA Colo.USA Conn.USA Del.USA D.C.USA Fla.USA Ga.USA IdahoUSA Ill.USA Ind.USA IowaUSA Kans.USA Ky.USA La.USA MaineUSA Md.USA Mass.USA Mich.USA Minn.USA Miss.USA Mo.USA Mont.USA Nebr.USA Nev.USA N.H.USA N.J.USA N.Mex.USA N.Y.USA N.C.USA N.Dak.USA OhioUSA Okla.USA Oreg.USA Pa.USA R.I.USA S.C.USA S.Dak.USA Tenn.USA Tex.USA UtahUSA Vt.USA Va.USA Wash.USA W.Va.USA Wis.USA Wyo.Canada Alta.Canada B.C.Canada Man.Canada N.B.Canada N.W.T.Canada N.S.Canada Ont.Canada P.E.I.Canada Que.Canada Sask.Canada Yukon
Discussion
Specimens of Ceratophyllum demersum with short basal spines or tubercles have been misidentified as C. submersum Linnaeus, a species not known in the New World despite reports to the contrary. Ceratophyllum demersum is the most common species of Ceratophyllum in North America and also the least likely to be found with fruit, its reproduction being primarily asexual. Predominantly low leaf order is, therefore, the most reliable means of identifying this species.
Noted for its prolific growth, Ceratophyllum demersum occasionally has attained status as a serious weed.

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