View source for Betula occidentalis

{{Treatment/ID
|accepted_name=Betula occidentalis
|accepted_authority=Hooker
|publications={{Treatment/Publication
|title=Fl. Bor.-Amer.
|place=2: 155. 1838
|year=1838
}}
|common_names=Water birch;river birch
|special_status={{Treatment/ID/Special_status
|code=E
|label=Endemic
}}{{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Betula fontinalis
|authority=Sargent
|rank=species
}} {{Treatment/ID/Synonym
|name=Betula fontinalis var. inopina
|authority=(Jepson) Jepson
|rank=variety
}} {{Treatment/ID/Synonym
|name=Betula microphylla var. fontinalis
|authority=(Sargent) M. E. Jones
|rank=variety
}} {{Treatment/ID/Synonym
|name=Betula occidentalis var. fecunda
|authority=(Britton) Fernald
|rank=variety
}} {{Treatment/ID/Synonym
|name=Betula occidentalis var. inopina
|authority=(Jepson) C. L. Hitchcock
|rank=variety
}} {{Treatment/ID/Synonym
|name=Betula papyrifera var. occidentalis
|authority=(Hooker) Sargent
|rank=variety
}} {{Treatment/ID/Synonym
|name=Betula papyrifera subsp. occidentalis
|authority=(Hooker) Hultén
|rank=subspecies
}}
|hierarchy=Betulaceae;Betulaceae subfam. Betuloideae;Betula;Betula occidentalis
|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 occidentalis]]</div></div>
|volume=Volume 3
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Shrubs,</b> spreading, to 10 m. <b>Bark</b> dark reddish brown to bronze, smooth, close, not readily exfoliating; lenticels pale, horizontally expanded. <b>Twigs</b> without the odor or taste of wintergreen, glabrous to sparsely pubescent, covered with conspicuous, reddish, resinous glands. <b>Leaf</b> blade broadly ovate to rhombic-ovate with 2–6 pairs of lateral veins, 2–5.8 × 1–4.5 cm, base truncate to rounded or cuneate, margins sharply and coarsely serrate or irregularly doubly serrate, teeth mostly long and sharp, basal portion untoothed, apex acute to occasionally short-acuminate; surfaces abaxially sparsely to moderately pubescent, covered with minute, resinous glands. <b>Infructescences</b> erect to nearly pendulous, cylindric, 2–3(–3.9) × 0.8–1.5 cm, shattering with fruits in fall; scales glabrous, ciliate, lobes diverging at middle, central lobe narrower and longer than ascending lateral lobes. <b>Samaras</b> with wings broader than body, broadest near summit, extended beyond body apically. <b>2n</b> = 28.</span><!--

-->{{Treatment/Body
|phenology=Flowering late spring.
|habitat=Montane stream banks, slopes, and ridges, also in moist open woods, at edges of marshes, along lakeshores, and in wet swales
|elevation=100–3000 m
|distribution=Alta.;B.C.;Man.;N.W.T.;Ont.;Sask.;Yukon;Alaska;Ariz.;Calif.;Colo.;Idaho;Mont.;Nebr.;Nev.;N.Mex.;N.Dak.;Oreg.;S.Dak.;Utah;Wash.;Wyo.
|discussion=<p><i>Betula occidentalis</i> is a common, streamside, shrubby birch throughout much of the Rocky Mountains, extending eastward to northwestern Ontario. It has been widely known by the later name B. fontinalis because of questions concerning the legitimacy of Hooker's epithet (J. R. Dugle 1966). Recent changes to the International Code of Botanical Nomenclature (W. Greuter et al. 1994) have clarified the situation, however, and the consensus now is that the earlier name is correct. E. Hultén (1968) believed that the species in Alaska that has been called <i>B. occidentalis</i> consists of an extensive hybrid swarm between <i>B. neoalaskana</i> (as B. resinifera) and <i>B. glandulosa</i>. The studies of J. R. Dugle (1966) do not support a hybrid origin of <i>B. occidentalis</i> in other parts of its range. Additional study will be needed to resolve this problem, both in Alaska and southward.</p><!--
--><p><i>Betula</i> ×utahensis Britton (= <i>B. occidentalis</i> Hooker × <i>B. papyrifera</i> Marshall) is a common hybrid marked by intermediate characteristics.</p><!--
--><p><i>Betula papyrifera</i> Marshall var. subcordata (Rydberg) Sargent, formerly recognized in several state, provincial, and regional floras, consists of introgressants of <i>B. occidentalis</i> into <i>B. papyrifera</i> (J. R. Dugle 1966).</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Betula occidentalis
|authority=Hooker
|rank=species
|parent rank=genus
|synonyms=Betula fontinalis;Betula fontinalis var. inopina;Betula microphylla var. fontinalis;Betula occidentalis var. fecunda;Betula occidentalis var. inopina;Betula papyrifera var. occidentalis;Betula papyrifera subsp. occidentalis
|basionyms=
|family=Betulaceae
|phenology=Flowering late spring.
|habitat=Montane stream banks, slopes, and ridges, also in moist open woods, at edges of marshes, along lakeshores, and in wet swales
|elevation=100–3000 m
|distribution=Alta.;B.C.;Man.;N.W.T.;Ont.;Sask.;Yukon;Alaska;Ariz.;Calif.;Colo.;Idaho;Mont.;Nebr.;Nev.;N.Mex.;N.Dak.;Oreg.;S.Dak.;Utah;Wash.;Wyo.
|reference=None
|publication title=Fl. Bor.-Amer.
|publication year=1838
|special status=Endemic;Illustrated
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V3/V3_655.xml
|subfamily=Betulaceae subfam. Betuloideae
|genus=Betula
|species=Betula occidentalis
}}<!--

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