View source for Elodea

{{Treatment/ID
|accepted_name=Elodea
|accepted_authority=Michaux
|publications={{Treatment/Publication
|title=Flora Boreali-Americana
|place=1: 20. 1803
|year=1803
}}
|common_names=Water-weed
|basionyms=
|synonyms=
|hierarchy=Hydrocharitaceae;Elodea
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Hydrocharitaceae]]</div><div class="higher-taxon"><small>genus</small>[[Elodea]]</div></div>
|etymology=Greek helodes, marshy
|volume=Volume 22
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism duration;whole_organism growth form"><b>Plants </b>perennial, of fresh waters.</span> <span class="statement" id="st-d0_s1" data-properties="rhizome presence;stolon presence"><b>Rhizomes </b>and stolons absent.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem architecture;stem architecture;stem architecture;stem shape"><b>Erect </b>stems rooted in substrate, branched or unbranched, elongate.</span> <span class="statement" id="st-d0_s3" data-properties="leaf position;leaf arrangement;leaf quantity;leaf arrangement;leaf location;leaf architecture;proximalmost node quantity"><b>Leaves </b>cauline, whorled, 3–7 at each node, or leaves opposite at 4+ proximalmost nodes, submersed, sessile;</span> <span class="statement" id="st-d0_s4" data-properties="blade shape;apex shape">blade linear to linear-lanceolate, apex acute;</span> <span class="statement" id="st-d0_s5" data-properties="">midvein without lacunae along side (s), blade uniform in color throughout;;</span> <span class="statement" id="st-d0_s6" data-properties="blade coloration;blade position">abaxial surfacely without prickles or aerenchyma;</span> <span class="statement" id="st-d0_s7" data-properties="intravaginal squamule architecture or shape">intravaginal squamules entire.</span> <span class="statement" id="st-d0_s8" data-properties="inflorescence architecture or arrangement or growth form;inflorescence architecture"><b>Inflorescences </b>solitary, sessile;</span> <span class="statement" id="st-d0_s9" data-properties="spathe architecture">spathes not winged.</span> <span class="statement" id="st-d0_s10" data-properties="flower reproduction;flower architecture;flower architecture;flower reproduction;flower architecture;floral-tube base shape"><b>Flowers </b>unisexual, staminate and pistillate on different plants, or rarely bisexual, usually projected to surface of water by elongate floral-tube base, sessile;</span> <span class="statement" id="st-d0_s11" data-properties="petal coloration">petals white.</span> <span class="statement" id="st-d0_s12" data-properties="flower architecture;filament fusion;filament quantity;filament position;filament length"><b>Staminate </b>flowers: filaments distinct or 3 inner connate ½ their length;</span> <span class="statement" id="st-d0_s13" data-properties="flower architecture;anther shape">anthers oval;</span> <span class="statement" id="st-d0_s14" data-properties="flower architecture">pollen in monads or tetrads.</span> <span class="statement" id="st-d0_s15" data-properties="flower architecture;ovary architecture or structure in adjective form"><b>Pistillate </b>flowers: ovary 1-locular;</span> <span class="statement" id="st-d0_s16" data-properties="flower architecture;style quantity;style shape">styles 3, not 2-fid.</span> <span class="statement" id="st-d0_s17" data-properties="fruit shape;fruit architecture or pubescence or relief;fruit dehiscence"><b>Fruits </b>ovoid to lance-ellipsoid, smooth, dehiscing irregularly.</span> <span class="statement" id="st-d0_s18" data-properties="seed shape;seed pubescence"><b>Seeds </b>cylindric to fusiform, glabrous to hirsute.</span><!--

-->{{Treatment/Body
|distribution=North America;Central America;South America;Europe
|discussion=<p>An additional name, Elodea schweinitzii (G. Planchon) Caspary, has appeared in North American literature. Although it was accepted by some (H. St. John 1965), others stated, "Elodea schweinitzii is something of a taxonomist's nightmare" (C. D. K. Cook and K. Urmi-K&ouml;nig 1985). The few collections referable to the name are exceedingly variable, so variable in fact that the authors added, "the main character is variability itself." I am following Cook and Urmi-K&ouml;nig in not accepting the taxon.</p><!--
--><p>Species 5 (3 in the flora).</p>
|tables=
|references={{Treatment/Reference
|id=cook1985b
|text=Cook, C. D. K. and K. Urmi-König. 1985. A revision of the genus Elodea (Hydrocharitaceae). Aquatic Bot. 21: 111--156. St.
}}{{Treatment/Reference
|id=john1920a
|text=John, H. 1920. The genus Elodea in New England. Rhodora 22: 17--29. St.
}}{{Treatment/Reference
|id=john1962a
|text=John, H. 1962. Monograph of the genus Elodea (Hydrocharitaceae): Part I. The species found in the Great Plains, the Rocky Mountains, and the Pacific states and provinces of North America. Res. Stud. State Coll. Wash. 30(2): 19--44. St.
}}{{Treatment/Reference
|id=john1965a
|text=John, H. 1965. Monograph of the genus Elodea: Part 4 and summary: The species of eastern and central North America. Rhodora 67: 1--—35, 155--180.
}}{{Treatment/Reference
|id=shinners1956a
|text=Shinners, L. H. 1956. Elodea correct without being conserved. Rhodora 58: 162.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Staminate spathes 4 mm or less; styles usually 2 mm or less; leaves usually less than 1.7 mm wide.
|[[Elodea nuttallii|Elodea nuttallii]]
|-id=key-0-1
|1
|Staminate spathes 6 mm or more; styles usually more than 2 mm; leaves usually more than 1.8 mm wide.
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Pollen in tetrads; staminate pedicels detaching before or during anthesis; anthers 3 mm or less; leaves mostly in 3s; seeds 4.5–5.7 mm or more.
|[[Elodea canadensis|Elodea canadensis]]
|-id=key-0-2
|2
|Pollen in monads; staminate pedicels remaining briefly following anthesis; anthers 3–4.5 mm; some leaves in 2s; seeds 4 mm or less.
|[[Elodea bifoliata|Elodea bifoliata]]
|}
</div></div><!--

-->{{#Taxon:
name=Elodea
|authority=Michaux
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Hydrocharitaceae
|distribution=North America;Central America;South America;Europe
|reference=cook1985b;john1920a;john1962a;john1965a;shinners1956a
|publication title=Flora Boreali-Americana
|publication year=1803
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/62857cf6bca5c4637d27b113da92d27dbf9962f4/V22/V22_602.xml
|genus=Elodea
|anther shape=oval
|apex shape=acute
|blade coloration=uniform
|blade position=abaxial
|blade shape=linear;linear-lanceolate
|filament fusion=distinct
|filament length=connate
|filament position=inner
|filament quantity=3
|floral-tube base shape=elongate
|flower architecture=pistillate;pistillate;staminate;staminate;staminate;sessile;pistillate;staminate
|flower reproduction=bisexual;unisexual
|fruit architecture or pubescence or relief=smooth
|fruit dehiscence=dehiscing
|fruit shape=ovoid;lance-ellipsoid
|inflorescence architecture=sessile
|inflorescence architecture or arrangement or growth form=solitary
|intravaginal squamule architecture or shape=entire
|leaf architecture=sessile
|leaf arrangement=opposite;whorled
|leaf location=submersed
|leaf position=cauline
|leaf quantity=3;7
|ovary architecture or structure in adjective form=1-locular
|petal coloration=white
|rhizome presence=absent
|seed pubescence=glabrous;hirsute
|seed shape=cylindric;fusiform
|spathe architecture=not winged
|stem architecture=unbranched;branched;rooted
|stem orientation=erect
|stem shape=elongate
|stolon presence=absent
|style quantity=3
|style shape=not 2-fid
|whole_organism duration=perennial
|whole_organism growth form=plant
}}<!--

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