View source for Isoëtes occidentalis

{{Treatment/ID
|accepted_name=Isoëtes occidentalis
|accepted_authority=L. F. Henderson
|publications={{Treatment/Publication
|title=Bull. Torrey Bot. Club
|place=27: 358. 1900
|year=1900
}}
|common_names=Western quillwort
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Isoëtes flettii
|authority=(A. A. Eaton) N. E. Pfeiffer
|rank=species
}} {{Treatment/ID/Synonym
|name=Isoëtes lacustris var. paupercula
|authority=Engelmann
|rank=variety
}} {{Treatment/ID/Synonym
|name=Isoëtes paupercula
|authority=(Engelmann) A. A. Eaton
|rank=species
}} {{Treatment/ID/Synonym
|name=Isoëtes piperi
|authority=A. A. Eaton
|rank=species
}}
|hierarchy=Isoëtaceae;Isoëtes;Isoëtes occidentalis
|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 occidentalis]]</div></div>
|volume=Volume 2
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism growth form or habitat;whole_organism growth form"><b>Plants </b>aquatic.</span> <span class="statement" id="st-d0_s1" data-properties="rootstock shape;rootstock shape"><b>Rootstock </b>nearly globose, 2-lobed.</span> <span class="statement" id="st-d0_s2" data-properties="leaf duration;leaf coloration;leaf coloration;leaf arrangement;leaf some measurement;leaf texture;leaf shape"><b>Leaves </b>evergreen, dark green, pale toward base, spirally arranged, to 20 cm, rigid, gradually tapering to tip.</span> <span class="statement" id="st-d0_s3" data-properties="sporangium quantity"><b>Velum </b>covering less than 1/2 sporangium.</span> <span class="statement" id="st-d0_s4" data-properties="sporangium wall coloration"><b>Sporangium </b>wall unpigmented.</span> <span class="statement" id="st-d0_s5" data-properties="megaspore diameter;megaspore shape;megaspore relief;megaspore relief;megaspore architecture"><b>Megaspores </b>500–700 μm diam., cristate, tuberculate, rugulate, or echinate with ridges, tubercles, or spines;</span> <span class="statement" id="st-d0_s6" data-properties="girdle architecture or pubescence or relief">girdle smooth.</span> <span class="statement" id="st-d0_s7" data-properties=""><b>Microspores </b>brown in mass, 35–45 μm, papillose to spinulose.</span> <span class="statement" id="st-d0_s8" data-properties="microspore coloration;microspore some measurement;microspore relief;microspore architecture or shape;2n chromosome quantity">2n = 66.</span><!--

-->{{Treatment/Body
|phenology=Spores mature in late summer.
|habitat=Lakes
|distribution=B.C.;Alaska;Calif.;Colo.;Idaho;Mont.;Oreg.;Utah;Wash.;Wyo.
|discussion=<p>Megaspores of Isoëtes occidentalis are variable in wall pattern. Populations exist with rugulate or tuberculate megaspores and other population with cristate to echinate megaspores. Plants with thin-walled megaspores that crack easily have been called I. paupercula. Populations in which megaspores have short ridges and tubercles in a band along the equator have been called I. flettii. Populations with broad-based tubercles on the megaspores have been called I. piperi. The variation in megaspore pattern may indicate multiple allopolyploid origins for I. occidentalis.</p><!--
--><p>The general aspect of Isoëtes occidentalis and its tough, dark green leaves suggested to early workers an affinity with I. lacustris.</p><!--
--><p>Isoëtes occidentalis hybridizes with I. bolanderi, I. echinospora, and I. maritima [ = I. x truncata (A. A. Eaton) Clute].</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Isoëtes occidentalis
|authority=L. F. Henderson
|rank=species
|parent rank=genus
|synonyms=Isoëtes flettii;Isoëtes lacustris var. paupercula;Isoëtes paupercula;Isoëtes piperi
|basionyms=
|family=Isoëtaceae
|phenology=Spores mature in late summer.
|habitat=Lakes
|distribution=B.C.;Alaska;Calif.;Colo.;Idaho;Mont.;Oreg.;Utah;Wash.;Wyo.
|reference=None
|publication title=Bull. Torrey Bot. Club
|publication year=1900
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V2/V2_479.xml
|genus=Isoëtes
|species=Isoëtes occidentalis
|2n chromosome quantity=66
|girdle architecture or pubescence or relief=smooth
|leaf arrangement=arranged
|leaf coloration=pale;dark green
|leaf duration=evergreen
|leaf shape=tapering
|leaf some measurement=0cm;20cm
|leaf texture=rigid
|megaspore architecture=echinate
|megaspore diameter=500um;700um
|megaspore relief=rugulate;tuberculate
|megaspore shape=cristate
|microspore architecture or shape=spinulose
|microspore coloration=brown
|microspore relief=papillose
|microspore some measurement=35um;45um
|rootstock shape=2-lobed;globose
|sporangium quantity=0;1/2
|sporangium wall coloration=unpigmented
|whole_organism growth form=plant
|whole_organism growth form or habitat=aquatic
}}<!--

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