View source for Ceratophyllum

{{Treatment/ID
|accepted_name=Ceratophyllum
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 992. 175
}}{{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 428. 1754
|year=1754
}}
|common_names=Hornwort;cornifle
|basionyms=
|synonyms=
|hierarchy=Ceratophyllaceae;Ceratophyllum
|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>
|etymology=Greek ceratos, horn, and phyllon, leaf
|volume=Volume 3
|mention_page=
|treatment_page=page 82
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants,</b> submersed perennials. <b>Stems</b> suspended or anchored by branches buried in substrate; branches 0-3 per node. <b>Leaves</b> 3-11 per whorl, cauline; petiole inconspicuous. <b>Leaf</b> blade simple or forked into linear-filiform, denticulate segments. <b>Inflorescences</b> extra-axillary, alternating with leaves. <b>Flowers</b>: bracts basally connate, foliaceous; pedicel less than 1 mm or essentially absent. <b>Staminate</b> flowers: anther 2-locular, connective projecting as apical appendage. <b>Pistillate</b> flowers: ovary tapering to persistent, spinelike style; ovule pendulous. <b>Achene</b> ellipsoid, moderately compressed, surface smooth or tuberculate, basal or marginal spines (or both) present or absent, terminal spine present, marginal wing present or absent. <b>x</b> = 12, 19, 20.</span><!--

-->{{Treatment/Body
|discussion=<p>Useful in identification of species of <i>Ceratophyllum</i> are leaf-forking characteristics. Leaves with no forking are "0-order"; they consist only of a primary segment. Those forking once are "1st-order"; their ultimate segments are secondary. Those in which at least one secondary segment forks are "2d-order"; their ultimate segments are tertiary. Those in which at least one tertiary segment forks are "3d-order"; their ultimate segments are quaternary. Those in which at least one quaternary segment forks are "4th order."</p><!--
--><p>Plumule features used in the key below are observable through dissection of softened (soaked) seeds removed from achenes.</p>
|tables=
|references={{Treatment/Reference
|id=fassett1953b
|text=Fassett, N. C. 1953. North American Ceratophyllum. Comun. Inst. Trop. Invest. Ci. Univ. El Salvador 2: 25-45.
}}{{Treatment/Reference
|id=herendeen1990a
|text=Herendeen, P. S., D. H. Les, and D. L. Dilcher. 1990. Fossil Ceratophyllum (Ceratophyllaceae) from the Tertiary of North America. Amer. J. Bot. 77: 7-16.
}}{{Treatment/Reference
|id=jones1931a
|text=Jones, E. N. 1931. The morphology and biology of Ceratophyllum demersum. Stud. Nat. Hist. Iowa Univ. 13: 11-55.
}}{{Treatment/Reference
|id=les1985a
|text=Les, D. H. 1985. The taxonomic significance of plumule morphology in Ceratophyllum (Ceratophyllaceae). Syst. Bot. 10: 338-346.
}}{{Treatment/Reference
|id=les1986a
|text=Les, D. H. 1986. The phytogeography of Ceratophyllum demersum and C. echinatum in glaciated North America. Canad. J. Bot. 64: 498-509.
}}{{Treatment/Reference
|id=les1986b
|text=Les, D. H. 1986b. The evolution of achene morphology in Ceratophyllum (Ceratophyllaceae), I. Fruit spine variation and relationships of C. demersum, C. submersum, and C. apiculatum. Syst. Bot. 11: 549-558.
}}{{Treatment/Reference
|id=les1988b
|text=Les, D. H. 1988b. The evolution of achene morphology in Ceratophyllum (Ceratophyllaceae), II. Fruit variation and systematics of the "spiny-margined" group. Syst. Bot. 13: 73-86.
}}{{Treatment/Reference
|id=les1988c
|text=Les, D. H. 1988c. The evolution of achene morphology in Ceratophyllum (Ceratophyllaceae), III. Relationships of the "facially-spined" group. Syst. Bot. 13: 509-518.
}}{{Treatment/Reference
|id=les1989a
|text=Les, D. H. 1989. The evolution of achene morphology in Ceratophyllum (Ceratophyllaceae), IV. Summary of proposed relationships and evolutionary trends. Syst. Bot. 14: 254-262.
}}{{Treatment/Reference
|id=lowden1978a
|text=Lowden, R. M. 1978. Studies in the submerged genus Ceratophyllum L. in the neotropics. Aquat. Bot. 4: 127-142.
}}{{Treatment/Reference
|id=muenscher1940a
|text=Muenscher, W. C. 1940. Fruits and seedlings of Ceratophyllum. Amer. J. Bot. 27: 231-233.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Forking of largest leaves 1st or 2d order (rarely 3d order); leaves coarse-textured, marginal denticles usually strongly raised on broad base of green tissue; achene margin wingless, basal spines or tubercles 2 (rarely absent).
|[[Ceratophyllum demersum|Ceratophyllum demersum]]
|-id=key-0-1
|1
|Forking of largest leaves 3d or 4th order; leaves fine-textured, marginal denticles not raised on broad base of green tissue, sometimes nearly absent; achene margin winged, spines (0–)2–20, 0.1–6.5 mm, basal spines 2 (rarely absent).
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|First leaves of plumule simple; achene body (excluding terminal spine) 3–4.5 mm; Florida, Georgia, North Carolina.
|[[Ceratophyllum muricatum|Ceratophyllum muricatum]]
|-id=key-0-2
|2
|First leaves of plumule forked; achene body (excluding terminal spine) 4.5–6 mm; widespread in North America.
|[[Ceratophyllum echinatum|Ceratophyllum echinatum]]
|}
</div></div><!--

-->{{#Taxon:
name=Ceratophyllum
|author=
|authority=Linnaeus
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Ceratophyllaceae
|reference=fassett1953b;herendeen1990a;jones1931a;les1985a;les1986a;les1986b;les1988b;les1988c;les1989a;lowden1978a;muenscher1940a
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=;1754
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/8f726806613d60c220dc4493de13607dd3150896/coarse_grained_fna_xml/V3/V3_139.xml
|genus=Ceratophyllum
}}<!--

-->[[Category:Treatment]][[Category:Ceratophyllaceae]]