View source for Ceratophyllum echinatum

{{Treatment/ID
|accepted_name=Ceratophyllum echinatum
|accepted_authority=A. Gray
|publications={{Treatment/Publication
|title=Ann. Lyceum Nat. Hist. New York
|place=4: 49. 1837
|year=1837
}}
|common_names=Hornwort;cornifle échinée
|special_status={{Treatment/ID/Special_status
|code=E
|label=Endemic
}}{{Treatment/ID/Special_status
|code=F
|label=Selected by author to be illustrated
}}{{Treatment/ID/Special_status
|code=W
|label=Weedy
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Ceratophyllum demersum var. echinatum
|authority=(A. Gray) A. Gray
}} {{Treatment/ID/Synonym
|name=Ceratophyllum submersum var. echinatum
|authority=(A. Gray) Wilmot-Dear
}}
|hierarchy=Ceratophyllaceae;Ceratophyllum;Ceratophyllum echinatum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Ceratophyllaceae]]</div><div class="higher-taxon"><small>genus</small>[[Ceratophyllum]]</div><div class="higher-taxon"><small>species</small>[[Ceratophyllum echinatum]]</div></div>
|volume=Volume 3
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Stems </b>to 1 m; apical leaf whorls not densely crowded. <b>Leaves</b> dark green or olive-green, fine-textured. <b>Leaf</b> blade simple or forked into 2-10 ultimate segments (forking of largest leaves 3d or 4th order), proximal segments often conspicuously inflated, mature leaf whorls 25-55 mm diam., marginal denticles weak and inconspicuous, weakly exserted, not raised on broad base of green tissue; 1st leaves of plumule forked. <b>Achene</b> dark green or brown, body (excluding spines) 4.5-6 × 2.5-4.5 × 1.5-3 mm, basal spines 2 (rarely absent), straight or curved, 1-5 mm, marginal spines 2-13, 0.5-6.5 mm, terminal spine straight, 1.5-7.5 mm, margins winged. <b>2n</b> = 24.</span><!--

-->{{Treatment/Body
|phenology=Flowering spring–summer.
|habitat=Fresh water of lakes, ponds, marshes, swamps
|elevation=0-500 m
|distribution=B.C.;Man.;N.B.;N.S.;Ont.;Que.;Ala.;Ark.;Conn.;Del.;D.C.;Fla.;Ga.;Ill.;Ind.;Iowa;Kans.;Ky.;La.;Maine;Md.;Mass.;Mich.;Minn.;Miss.;Mo.;N.H.;N.J.;N.Y.;N.C.;Ohio;Okla.;Oreg.;Pa.;R.I.;S.C.;Tenn.;Tex.;Vt.;Va.;Wash.;W.Va.;Wis.
|discussion=<p>Principally an eastern North American species–and the only species of its genus endemic to North America–<i>Ceratophyllum echinatum</i> is disjunct in the Pacific Northwest as a result of repeated Pleistocene glaciation. The habitats of <i>C. echinatum</i> are typically more acidic (avg. pH 6.6) than those of <i>C. demersum</i> (avg. pH 7.4). The two species only rarely coexist. <i>Ceratophyllum echinatum</i> also thrives in cooler, clearer, and more oligotrophic water than <i>C. demersum</i> and often is found in more ephemeral sites, such as shrub swamps (e.g., with Cephalanthus occidentalis) and beaver ponds.</p><!--
--><p>This species, relatively uncommon, is fast disappearing from much of its range because of habitat alteration or destruction and the introduction of nonindigenous species; steps should be taken to secure its conservation. Unlike <i>Ceratophyllum demersum</i>, <i>C. echinatum</i> does not attain status as a serious weed.</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Ceratophyllum echinatum
|author=
|authority=A. Gray
|rank=species
|parent rank=genus
|synonyms=Ceratophyllum demersum var. echinatum;Ceratophyllum submersum var. echinatum
|basionyms=
|family=Ceratophyllaceae
|phenology=Flowering spring–summer.
|habitat=Fresh water of lakes, ponds, marshes, swamps
|elevation=0-500 m
|distribution=B.C.;Man.;N.B.;N.S.;Ont.;Que.;Ala.;Ark.;Conn.;Del.;D.C.;Fla.;Ga.;Ill.;Ind.;Iowa;Kans.;Ky.;La.;Maine;Md.;Mass.;Mich.;Minn.;Miss.;Mo.;N.H.;N.J.;N.Y.;N.C.;Ohio;Okla.;Oreg.;Pa.;R.I.;S.C.;Tenn.;Tex.;Vt.;Va.;Wash.;W.Va.;Wis.
|reference=None
|publication title=Ann. Lyceum Nat. Hist. New York
|publication year=1837
|special status=Endemic;Selected by author to be illustrated;Weedy
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse_grained_fna_xml/V3/V3_454.xml
|genus=Ceratophyllum
|species=Ceratophyllum echinatum
}}<!--

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