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-undefined" data-properties=""><b>Plants </b>aquatic. <b>Rootstock</b> nearly globose, 2-lobed. <b>Leaves</b> evergreen, dark green, pale toward base, spirally arranged, to 20 cm, rigid, gradually tapering to tip. <b>Velum</b> covering less than 1/2 sporangium. <b>Sporangium</b> wall unpigmented. <b>Megaspores</b> 500–700 μm diam., cristate, tuberculate, rugulate, or echinate with ridges, tubercles, or spines; girdle smooth. <b>Microspores</b> brown in mass, 35–45 μm, papillose to spinulose. <b>2n</b> = 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 <i>Isoëtes occidentalis</i> 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>I. occidentalis</i>.</p><!--
--><p>The general aspect of <i>Isoëtes occidentalis</i> and its tough, dark green leaves suggested to early workers an affinity with <i>I. lacustris</i>.</p><!--
--><p><i>Isoëtes occidentalis</i> hybridizes with <i>I. bolanderi</i>, <i>I. echinospora</i>, and <i>I. maritima</i> [ = 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://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V2/V2_479.xml
|genus=Isoëtes
|species=Isoëtes occidentalis
}}<!--

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