View source for Betula nana subsp. exilis

{{Treatment/ID
|accepted_name=Betula nana subsp. exilis
|accepted_authority=(Sukaczev) Hultén
|publications={{Treatment/Publication
|title=Fl. Alaska Yukon
|place=4: 579. 1944
|year=1944
}}
|common_names=Arctic dwarf birch
|basionyms={{Treatment/ID/Basionym
|name=Betula exilis
|authority=Sukaczev
|rank=species
|publication_title=Trudy Bot. Muz. Imp. Akad. Nauk
|publication_place=8: 213. 1911
}}
|synonyms={{Treatment/ID/Synonym
|name=Betula glandulosa var. sibirica
|authority=(Ledebour) C. K. Schneider
|rank=variety
}}
|hierarchy=Betulaceae;Betulaceae subfam. Betuloideae;Betula;Betula nana;Betula nana subsp. exilis
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Betulaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Betulaceae subfam. Betuloideae]]</div><div class="higher-taxon"><small>genus</small>[[Betula]]</div><div class="higher-taxon"><small>species</small>[[Betula nana]]</div><div class="higher-taxon"><small>subspecies</small>[[Betula nana subsp. exilis]]</div></div>
|volume=Volume 3
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Shrubs,</b> spreading, depressed, to 1 m. <b>Bark</b> reddish brown. <b>Twigs</b> glabrous to very sparsely pubescent, conspicuously resinous, with relatively few small, resinous glands. <b>Leaf</b> blade broadly orbiculate to reniform, 0.5–1.2 × 0.5–1.6 cm, base rounded to nearly cordate or cuneate; surfaces abaxially glabrous, occasionally with only a few small, resinous glands. <b>Infructescences</b> 0.5–1.2 × 0.5–0.7 cm; scales glabrous, lobes diverging distal to middle, held nearly parallel, center lobe ascending, slightly longer than lateral lobes. <b>2n</b> = 28.</span><!--

-->{{Treatment/Body
|phenology=Flowering late spring.
|habitat=Wet tundra and margins of bogs, terraces and open slopes
|elevation=0–2400 m
|distribution=Alta.;B.C.;Man.;N.W.T.;Sask.;Yukon;Alaska;n Asia.
|discussion=<p>The range of <i>Betula nana </i>subsp.<i> exilis</i> stretches through Siberia and across northwestern North America. It is sometimes confused with <i>Betula glandulosa</i> Michaux; it can be distinguished from that species by its usually much smaller, rounded to truncate-tipped leaves that have teeth all the way to the base (the base being mostly toothless in <i>B. glandulosa</i>). <i>Betula nana </i>subsp.<i> exilis</i> has been combined into <i>B. glandulosa</i> by several authors (E. H. Moss and J. G. Packer 1983; A. E. Porsild and W. J. Cody 1980). The two taxa hybridize and form a sometimes bewildering assortment of intermediates in the extensive region where their ranges overlap; they constitute well-defined entities away from the area of contact. The current treatment follows the view of E. Hultén (1968) that two distinct species of dwarf arctic birches inhabit northern North America. Little is understood, however, about the evolutionary or phytogeographic history of this complex, and many problems remain to be unraveled before a truly satisfactory classification can be attained.</p><!--
--><p>Western Eskimos used decoctions prepared from the leaves of <i>Betula nana </i>subsp.<i> exilis</i> to alleviate intestinal discomfort (D. E. Moerman 1986).</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Betula nana subsp. exilis
|authority=(Sukaczev) Hultén
|rank=subspecies
|parent rank=species
|synonyms=Betula glandulosa var. sibirica
|basionyms=Betula exilis
|family=Betulaceae
|phenology=Flowering late spring.
|habitat=Wet tundra and margins of bogs, terraces and open slopes
|elevation=0–2400 m
|distribution=Alta.;B.C.;Man.;N.W.T.;Sask.;Yukon;Alaska;n Asia.
|reference=None
|publication title=Fl. Alaska Yukon
|publication year=1944
|special status=
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V3/V3_503.xml
|subfamily=Betulaceae subfam. Betuloideae
|genus=Betula
|species=Betula nana
|subspecies=Betula nana subsp. exilis
}}<!--

-->[[Category:Treatment]][[Category:Betula nana]]