View source for Athyrium distentifolium var. americanum

{{Treatment/ID
|accepted_name=Athyrium distentifolium var. americanum
|accepted_authority=(Butters) Boivin
|publications={{Treatment/Publication
|title=Naturaliste Canad.
|place=93: 272. 1966.
}}
|common_names=American alpine lady fern;athyrie alpestre sous-espèce américaine
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Athyrium alpestre var. americanum
|authority=Butters
|rank=variety
}} {{Treatment/ID/Synonym
|name=Athyrium americanum
|authority=(Butters) Maxon
|rank=species
}} {{Treatment/ID/Synonym
|name=Athyrium americanum subsp. americanum
|authority=(Butters) Lellinger
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Athyrium alpestre var. gaspense
|authority=Fernald
|rank=variety
}} {{Treatment/ID/Synonym
|name=Athyrium distentifolium subsp. americanum
|authority=(Butters) Hultén
|rank=subspecies
}}
|hierarchy=Dryopteridaceae;Athyrium;Athyrium distentifolium;Athyrium distentifolium var. americanum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Dryopteridaceae]]</div><div class="higher-taxon"><small>genus</small>[[Athyrium]]</div><div class="higher-taxon"><small>species</small>[[Athyrium distentifolium]]</div><div class="higher-taxon"><small>variety</small>[[Athyrium distentifolium var. americanum]]</div></div>
|volume=Volume 2
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Stems </b>ascending or short-creeping. <b>Petiole</b> straw-colored or red-brown distally, (7–)10–30 cm, base dark red-brown to black with 2 rows of teeth, swollen; scales at base brown to dark brown, lanceolate or broadly lanceolate, 13 × 3(–5) mm. <b>Blade</b> narrowly elliptic or lanceolate, 2–3-pinnate-pinnatifid, 15–55(–65) × 3–25 cm, moderately narrowed proximally, broadest below middle, apex acuminate. <b>Pinnae</b> short-stalked, narrowly deltate to deltate-oblong, apex acute. <b>Pinnules</b> deeply pinnatifid, segments oblong, crenulate. <b>Rachis</b>, costae, and costules with small, pale brown scales. <b>Veins</b> pinnate. <b>Sori</b> round to elliptic; indusia absent or very minute, scalelike. <b>2n</b> = 80.</span><!--

-->{{Treatment/Body
|habitat=Wet talus slopes, rocky hillsides, alpine meadows
|elevation=600–3100 m
|distribution=Greenland;Alta.;B.C.;Nfld. and Labr. (Nfld.);Que.;Yukon;Alaska;Calif.;Colo.;Idaho;Mont.;Nev.;Oreg.;Utah;Wash.;Wyo.
|discussion=<p><i>Athyrium distentifolium </i>var.<i> americanum</i> differs from var. distentifolium of Europe in its more finely dissected leaves with crenulate pinnule-segments, relatively broader pinnae with abruptly larger basal pinnules, and much more rudimentary indusia, if any. Japanese plants are more similar to <i></i>var.<i> americanum</i> than to var. distentifolium, and they need further study.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Athyrium distentifolium var. americanum
|authority=(Butters) Boivin
|rank=variety
|parent rank=species
|synonyms=Athyrium alpestre var. americanum;Athyrium americanum;Athyrium americanum subsp. americanum;Athyrium alpestre var. gaspense;Athyrium distentifolium subsp. americanum
|basionyms=
|family=Dryopteridaceae
|habitat=Wet talus slopes, rocky hillsides, alpine meadows
|elevation=600–3100 m
|distribution=Greenland;Alta.;B.C.;Nfld. and Labr. (Nfld.);Que.;Yukon;Alaska;Calif.;Colo.;Idaho;Mont.;Nev.;Oreg.;Utah;Wash.;Wyo.
|reference=None
|publication title=Naturaliste Canad.
|publication year=
|special status=
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V2/V2_500.xml
|genus=Athyrium
|species=Athyrium distentifolium
|variety=Athyrium distentifolium var. americanum
}}<!--

-->[[Category:Treatment]][[Category:Athyrium distentifolium]]