View source for Potamogeton illinoensis

{{Treatment/ID
|accepted_name=Potamogeton illinoensis
|accepted_authority=Morong
|publications={{Treatment/Publication
|title=Botanical Gazette
|place=5: 50. 1880
|year=1880
}}
|common_names=Illinois pondweed;potamot de I’Illinois
|basionyms=
|synonyms=
|hierarchy=Potamogetonaceae;Potamogeton;Potamogeton illinoensis
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Potamogetonaceae]]</div><div class="higher-taxon"><small>genus</small>[[Potamogeton]]</div><div class="higher-taxon"><small>species</small>[[Potamogeton illinoensis]]</div></div>
|volume=Volume 22
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Rhizomes </b>present. <b>Cauline</b> stems terete, without spots, 28–120 cm; nodal glands absent. <b>Turions</b> absent. <b>Leaves</b> both submersed and floating or the floating absent, &#177; spirally arranged. <b>Submersed</b> leaves sessile or petiolate, lax; stipules persistent, conspicuous, convolute, free from blade, light brown to red-brown, not ligulate, 1–8 cm, not fibrous, not shredding at tip, apex acuminate; petioles if present 0.5–4 cm; blade red-brown to light green, elliptic to lanceolate or rarely linear, often arcuate, 5–20 cm × 2–45 mm, base acute, margins entire, often crispate, apex not hoodlike, acute-mucronate, lacunae in 2–5 rows each side midrib; veins 7–19. <b>Floating</b> leaves: petioles continuous in color to apex, 2–9 cm; blade adaxially light green, elliptic to oblong-elliptic, 4–19 cm × 20–65 mm, base cuneate, apex round-mucronate; veins 13–29. <b>Inflorescences</b> emersed, unbranched; peduncles not dimorphic, terminal or axillary, erect to ascending, cylindric, 4–30 cm; spikes not dimorphic, cylindric, 25–70 mm. <b>Fruits</b> sessile, grayish green to olive green, obovoid to ovoid, laterally compressed, abaxially keeled, laterally ridged, 2.5–3.6 × 2.1–3 mm, abaxial keel well developed, lateral ridges without points; beak erect to slightly recurved, 0.5–0.8 mm; sides without basal tubercles; embryo with 1 full spiral. <b>2n</b> = 104.</span><!--

-->{{Treatment/Body
|phenology=Flowering and fruiting summer–fall.
|habitat=Alkaline waters of streams, rivers, lakes, ponds, and sloughs
|elevation=0–2700 m
|distribution=B.C.;Man.;N.B.;N.W.T.;Ont.;Que.;Ala.;Ark.;Calif.;Colo.;Conn.;Fla.;Ga.;Ill.;Ind.;Iowa;Kans.;Ky.;Md.;Mass.;Mich.;Minn.;Mo.;Mont.;Nebr.;N.H.;N.J.;N.Y.;N.C.;Okla.;Ohio;Oreg.;Pa.;S.C.;S.Dak.;Tex.;Utah;Vt.;Va.;Wash.;W.Va.;Wis.;Wyo.;Mexico;West Indies;Central America;South America.
|discussion=<p><i>Potamogeton illinoensis</i> and <i>P. gramineus</i> are often difficult to separate. Certainly, in the extreme of each they are easily separated, but they continually grade into each other. Features to look for are the acute-mucronate apex of the submersed leaves of <i>P. illinoensis</i> and the acuminate apex for <i>P. gramineus</i>. Also, the number of veins seems to work as well.</p><!--
--><p>Three hybrids, <i>Potamogeton illinoensis</i> × <i>P. nodosus</i> (= P. × faxonii Morong), <i>P. amplifolius</i> × <i>P. illinoensis</i> (= P. × scoliophyllus Hagstr&ouml;m), and <i>P. gramineus</i> × <i>P. illinoensis</i> [= P. × spathuliformis (J. W. Robbins) Morong], have been described.</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Potamogeton illinoensis
|authority=Morong
|rank=species
|parent rank=genus
|synonyms=
|basionyms=
|family=Potamogetonaceae
|phenology=Flowering and fruiting summer–fall.
|habitat=Alkaline waters of streams, rivers, lakes, ponds, and sloughs
|elevation=0–2700 m
|distribution=B.C.;Man.;N.B.;N.W.T.;Ont.;Que.;Ala.;Ark.;Calif.;Colo.;Conn.;Fla.;Ga.;Ill.;Ind.;Iowa;Kans.;Ky.;Md.;Mass.;Mich.;Minn.;Mo.;Mont.;Nebr.;N.H.;N.J.;N.Y.;N.C.;Okla.;Ohio;Oreg.;Pa.;S.C.;S.Dak.;Tex.;Utah;Vt.;Va.;Wash.;W.Va.;Wis.;Wyo.;Mexico;West Indies;Central America;South America.
|reference=None
|publication title=Botanical Gazette
|publication year=1880
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V22/V22_150.xml
|genus=Potamogeton
|species=Potamogeton illinoensis
}}<!--

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