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-d0_s0" data-properties="stem orientation;stem orientation"><b>Stems </b>ascending or short-creeping.</span> <span class="statement" id="st-d0_s1" data-properties="petiole coloration;petiole coloration;petiole atypical some measurement;petiole some measurement;base coloration;base shape;row quantity"><b>Petiole </b>straw-colored or redbrown distally, (7–) 10–30 cm, base dark redbrown to black with 2 rows of teeth, swollen;</span> <span class="statement" id="st-d0_s2" data-properties="scale shape;scale shape;scale length;scale atypical width;scale width;base coloration">scales at base brown to dark-brown, lanceolate or broadly lanceolate, 13 × 3 (–5) mm.</span> <span class="statement" id="st-d0_s3" data-properties="blade shape;blade shape;blade shape;blade atypical length;blade length;blade width;blade shape;blade width;apex shape"><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.</span> <span class="statement" id="st-d0_s4" data-properties="pinna architecture;pinna shape;apex shape"><b>Pinnae </b>short-stalked, narrowly deltate to deltate-oblong, apex acute.</span> <span class="statement" id="st-d0_s5" data-properties="pinnule shape;segment shape;segment shape"><b>Pinnules </b>deeply pinnatifid, segments oblong, crenulate.</span> <span class="statement" id="st-d0_s6" data-properties="scale size;scale coloration"><b>Rachis,</b> costae, and costules with small, pale-brown scales.</span> <span class="statement" id="st-d0_s7" data-properties="vein architecture or shape"><b>Veins </b>pinnate.</span> <span class="statement" id="st-d0_s8" data-properties="sorus shape"><b>Sori </b>round to elliptic;</span> <span class="statement" id="st-d0_s9" data-properties="">indusia absent or very minute, scalelike.</span> <span class="statement" id="st-d0_s10" data-properties="indusium presence;indusium size;indusium shape;2n chromosome quantity">2n = 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>Athyrium distentifolium var. americanum 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 var. americanum 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://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V2/V2_500.xml
|genus=Athyrium
|species=Athyrium distentifolium
|variety=Athyrium distentifolium var. americanum
|2n chromosome quantity=80
|apex shape=acute;acuminate
|base coloration=brown;dark-brown
|base shape=swollen
|blade atypical length=55cm;65cm
|blade length=15cm;55cm
|blade shape=narrowed;2-3-pinnate-pinnatifid;lanceolate;elliptic
|blade width=broadest;3cm;25cm
|indusium presence=absent
|indusium shape=scale-like
|indusium size=minute
|petiole atypical some measurement=7cm;10cm
|petiole coloration=redbrown;straw-colored
|petiole some measurement=10cm;30cm
|pinna architecture=short-stalked
|pinna shape=narrowly deltate;deltate-oblong
|pinnule shape=pinnatifid
|row quantity=2
|scale atypical width=3mm;5mm
|scale coloration=pale-brown
|scale length=13
|scale shape=lanceolate;lanceolate
|scale size=small
|scale width=3
|segment shape=crenulate;oblong
|sorus shape=round;elliptic
|stem orientation=short-creeping;ascending
|vein architecture or shape=pinnate
}}<!--

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