View source for Isoëtes riparia

{{Treatment/ID
|accepted_name=Isoëtes riparia
|accepted_authority=Engelmann ex A. Braun
|publications={{Treatment/Publication
|title=Flora
|place=29: 178. 1846
|year=1846
}}
|common_names=Shore quillwort;isoète riparien
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Isoëtes canadensis
|authority=(Engelmann) A. A. Eaton
}}{{Treatment/ID/Synonym
|name=Isoëtes saccharata
|authority=Engelmann
}}
|hierarchy=Isoëtaceae;Isoëtes;Isoëtes riparia
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Isoëtaceae]]</div><div class="higher-taxon"><small>genus</small>[[Isoëtes]]</div><div class="higher-taxon"><small>species</small>[[Isoëtes riparia]]</div></div>
|volume=Volume 2
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>usually aquatic, occasionally emergent. <b>Rootstock</b> nearly globose, 2-lobed. <b>Leaves</b> evergreen, bright green, pale toward base, spirally arranged, often twisted, to 35(–50) cm, pliant, gradually tapering to tip. <b>Velum</b> covering less than 1/2 of sporangium. <b>Sporangium</b> wall brown-streaked to completely brown. <b>Megaspores</b> white, 450-650 μm diam., cristate with isolated and branching, lamellate ridges; girdle obscure. <b>Microspores</b> gray to light brown in mass, 30–40 μm, tuberculate. <b>2n</b> = 44.</span><!--

-->{{Treatment/Body
|phenology=Spores mature late summer.
|habitat=Margins of lakes, ponds, and streams, tidal shores and estuaries
|distribution=Calcareous to slightly acidic substrates in fresh;usually oligotrophic;water;Ont.;Que.;Conn.;Del.;Fla.;Maine;Md.;Mass.;N.H.;N.J.;N.Y.;N.C.;Pa.;R.I.;S.C.;Vt.;Va.;W.Va.
|discussion=<p>Megaspore morphology, electrophoretic profiles of leaf enzymes, and chromosome number provide evidence that Isoëtes riparia is an allotetraploid, formed by chromosome doubling in I. x eatonii, the primary diploid hybrid between I. echinospora and I. engelmanii. The considerable variation in leaf and spore morphology possibly results from multiple allotetraploid origins.</p><!--
--><p>Isoëtes riparia hybridizes with I. echinospora [ = I. x dodgei A. A. Eaton]; I. engelmannii [ = I. x brittonii Brunton & W. C. Taylor]; I. lacustris [ = I. x jeffreyi D. M. Britton & Brunton); and I. tuckermanii.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Isoëtes riparia
|author=
|authority=Engelmann ex A. Braun
|rank=species
|parent rank=genus
|synonyms=Isoëtes canadensis;Isoëtes saccharata
|basionyms=
|family=Isoëtaceae
|phenology=Spores mature late summer.
|habitat=Margins of lakes, ponds, and streams, tidal shores and estuaries
|distribution=Calcareous to slightly acidic substrates in fresh;usually oligotrophic;water;Ont.;Que.;Conn.;Del.;Fla.;Maine;Md.;Mass.;N.H.;N.J.;N.Y.;N.C.;Pa.;R.I.;S.C.;Vt.;Va.;W.Va.
|reference=None
|publication title=Flora
|publication year=1846
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/9216fc802291cd3df363fd52122300479582ede7/coarse_grained_fna_xml/V2/V2_127.xml
|genus=Isoëtes
|species=Isoëtes riparia
}}<!--

-->[[Category:Treatment]][[Category:Isoëtes]]