View source for Brachythecium

{{Treatment/ID
|accepted_name=Brachythecium
|accepted_authority=Schimper in P. Bruch and W. P. Schimper
|publications={{Treatment/Publication
|title=in P. Bruch and W. P. Schimper, Bryol. Europ.
|place=6: 5, plates 535 – 555. 1853
|year=1853
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Chamberlainia
|authority=Grout
}}
|hierarchy=Brachytheciaceae;Brachythecium
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Brachytheciaceae]]</div><div class="higher-taxon"><small>genus</small>[[Brachythecium]]</div></div>
|etymology=Greek brachys, short, and theke, case, alluding to capsule
|volume=Volume 28
|mention_page=page 229, 405, 406, 407, 408, 409, 410, 417, 421, 433, 441, 456, 461, 655, 656, 657
|treatment_page=page 414
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>small to large, in loose to dense mats, light to dark green, sometimes whitish, yellowish, or brownish, pale stramineous to yellow-brown with age. <b>Stems</b> creeping, ascending, erect, or arching, not reddish, densely to loosely terete-foliate, rarely subcomplanate-foliate or julaceous, irregularly or sometimes regularly pinnate, branches terete-, subcomplanate-, or complanate-foliate; central strand present; pseudoparaphyllia acute to acuminate; axillary hairs of 2–4 cells, cells long, 3–6:1. <b>Stem</b> leaves appressed, erect, spreading, patent, or falcate-secund, loosely or tightly imbricate, rarely somewhat spaced, lanceolate, ovate, or triangular, slightly to strongly concave, strongly to weakly longitudinally plicate, or plicae irregular, appearing crumpled, or not plicate; base narrowly to broadly short- to long-decurrent; margins serrate, serrulate, or entire, teeth never recurved; apex abruptly or gradually tapered or acuminate, occasionally piliferous; costa to 40–80% leaf length, moderate to somewhat stout, terminal spine present or absent; alar cells usually differentiated, larger or smaller than basal cells, walls thin when cells enlarged, region conspicuous or not, more pellucid or otherwise more opaque; laminal cells usually linear, 8–15:1, occasionally 20:1 or 3–5:1, walls thin to moderately thick, rarely as thick as lumen (<i>B. cirrosum</i> and <i>B. turgidum</i>); basal cells shorter, often wider than more distal cells, walls usually moderately incrassate, region opaque or pellucid across base. <b>Branch</b> leaves usually smaller and narrower; apex more gradually acute or acuminate. <b>Sexual</b> condition autoicous or dioicous; perichaetial leaves reflexed, apex gradually or abruptly acuminate. <b>Seta</b> red-brown with some variation in color in different species, darker with age, rough or smooth. <b>Capsule</b> inclined, horizontal, or somewhat pendent (erect in <i>B. acuminatum</i>), color similar to that of seta, usually darker, ovate, elongate, or cylindric, straight to curved; annulus not separating or separating by fragments; operculum conic, sometimes broadly short-rostrate; peristome xerocastique, perfect (reduced in <i>B. acuminatum</i>). <b>Calyptra</b> naked. <b>Spores</b> 9–25 µm.</span><!--

-->{{Treatment/Body
|distribution=Nearly worldwide;high Arctic to tropics.
|discussion=<p>Species ca. 80 (21 in the flora).</p><!--
--><p>Many species of <i>Brachythecium</i> exhibit a broad range of variation. Inadequate collections make it difficult if not impossible to separate superficially similar species. Large plants with well-developed stem leaves and fertile collections are most often necessary for the correct identification of <i>Brachythecium</i>. The following key ignores many marginal morphotypes of widespread species, although some of these are discussed in detail in the comments. The present circumscription of <i>Brachythecium</i> is narrower than in previous floras as some species have been placed in <i>Sciuro-hypnum</i> (species related to <i>S. glaciale</i>, <i>S. populeum</i>, <i>S. reflexum</i>, and <i>S. starkei</i>) and <i>Brachytheciastrum</i> (species related to <i>B. collinum</i> and <i>B. velutinum</i>), following M. S. Ignatov and S. Huttunen (2002).</p>
|tables=
|references={{Treatment/Reference
|id=ignatov2008a
|text=Ignatov, M. S., I. A. Milyutina, and V. K. Bobrova. 2008. Problematic groups of Brachythecium and Eurhynchiastrum (Brachytheciaceae, Bryophyta) and taxonomic solutions suggested by nrITS sequences. Arctoa 17: 113–138.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Alar cells enlarged; often wet to mesic habitats
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Alar cells same size or smaller than adjacent basal cells, rarely slightly enlarged; mesic to xeric habitats
|[[#key-0-8| > 8]]
|-id=key-0-2
|2
|Sexual condition autoicous
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Sexual condition dioicous
|[[#key-0-5| > 5]]
|-id=key-0-3
|3
|Setae rough; leaf margins serrulate to serrate; mesic habitats, deciduous forests of e North America.
|[[Brachythecium rutabulum|Brachythecium rutabulum]]
|-id=key-0-3
|3
|Setae smooth; leaf margins subentire or evenly serrulate; arctic and wetland species
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Stem leaves ovate; apices abruptly acuminate; margins serrulate; Alaska.
|[[Brachythecium boreale|Brachythecium boreale]]
|-id=key-0-4
|4
|Stem leaves ovate-triangular; apices gradually tapered or gradually acuminate; margins minutely serrulate to subentire; widespread in wet habitats.
|[[Brachythecium acutum|Brachythecium acutum]]
|-id=key-0-5
|5
|Leaf margins entire to slightly serrulate; setae unknown; Alaska.
|[[Brachythecium udum|Brachythecium udum]]
|-id=key-0-5
|5
|Leaf margins serrulate to serrate, rarely subentire; setae rough; widespread
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Leaves narrow, stem leaves 2-3:1; branch leaves 3-4:1.
|[[Brachythecium asperrimum|Brachythecium asperrimum]]
|-id=key-0-6
|6
|Leaves broad, stem leaves 1.5-2.5(-3):1; branch leaves 2-3:1
|[[#key-0-7| > 7]]
|-id=key-0-7
|7
|Alar regions not large, not saclike, enlarged cells separated from margin.
|[[Brachythecium frigidum|Brachythecium frigidum]]
|-id=key-0-7
|7
|Alar regions large, somewhat saclike, enlarged cells extending almost to margins.
|[[Brachythecium rivulare|Brachythecium rivulare]]
|-id=key-0-8
|8
|Leaf apices abruptly contracted, acumina filiform
|[[#key-0-9| > 9]]
|-id=key-0-8
|8
|Leaf apices gradually tapered, often long-acuminate
|[[#key-0-11| > 11]]
|-id=key-0-9
|9
|Sexual condition autoicous; basal laminal cell walls thick.
|[[Brachythecium turgidum|Brachythecium turgidum]]
|-id=key-0-9
|9
|Sexual condition dioicous; basal laminal cell walls weakly to moderately thick
|[[#key-0-10| > 10]]
|-id=key-0-10
|10
|Alar regions opaque or moderately pellucid, cells subquadrate; laminal cells 30-80(-100) × 6-7 µm.
|[[Brachythecium cirrosum|Brachythecium cirrosum]]
|-id=key-0-10
|10
|Alar regions ± pellucid, cells short-rectangular; laminal cells 40-80 × 8-12 µm.
|[[Brachythecium brandegeei|Brachythecium brandegeei]]
|-id=key-0-11
|11
|Plants small; stem leaves 0.6-1.4 × 0.4-0.6 mm; basal and alar cells almost undifferentiated; setae rough; California, Oregon.
|[[Brachythecium bolanderi|Brachythecium bolanderi]]
|-id=key-0-11
|11
|Plants and leaves usually medium-sized to large, if smaller then basal or alar cells distinctly differentiated; setae smooth (rough in B. campestre); widespread
|[[#key-0-12| > 12]]
|-id=key-0-12
|12
|Leaf margins serrulate to serrate, occasionally nearly entire
|[[#key-0-13| > 13]]
|-id=key-0-12
|12
|Leaf margins entire, subentire, or with very small teeth that do not enlarge in acumen
|[[#key-0-18| > 18]]
|-id=key-0-13
|13
|Alar regions not clearly differentiated; basal laminal cells in 3-8 rows, markedly different from more distal cells
|[[#key-0-14| > 14]]
|-id=key-0-13
|13
|Alar regions ± clearly delimited; basal laminal cells in 1-3 rows, not markedly different from more distal cells
|[[#key-0-16| > 16]]
|-id=key-0-14
|14
|Stem leaves deeply plicate; basal laminal cells (6-)8-11 µm wide, regions opaque.
|[[Brachythecium laetum|Brachythecium laetum]]
|-id=key-0-14
|14
|Stem leaves not to moderately plicate; basal laminal cells 11-16(-19)µm wide, regions usually pellucid
|[[#key-0-15| > 15]]
|-id=key-0-15
|15
|Plants small; stem leaves 1-1.6 × 0.3-0.6 mm.
|[[Brachythecium acuminatum|Brachythecium acuminatum]]
|-id=key-0-15
|15
|Plants medium-sized to moderately large; stem leaves (1.7-)2-2.8 × 0.6-0.9 mm.
|[[Brachythecium rotaeanum|Brachythecium rotaeanum]]
|-id=key-0-16
|16
|Leaves broadly ovate; apices gradually to abruptly long-acuminate; leaves 1.1-1.5(-1.9) × 0.5-0.7(-0.8) mm; sw United States.
|[[Brachythecium ruderale|Brachythecium ruderale]]
|-id=key-0-16
|16
|Leaves ovate-triangular or ovate-lanceolate; apices gradually tapered or acuminate; leaves 1.5-2.6 × 0.5-1.2 mm; widespread
|[[#key-0-17| > 17]]
|-id=key-0-17
|17
|Setae rough or occasionally smooth; leaves broadest at 1/9-1/7 leaf length.
|[[Brachythecium campestre|Brachythecium campestre]]
|-id=key-0-17
|17
|Setae smooth; leaves broadest at 1/10-1/7 leaf length.
|[[Brachythecium salebrosum|Brachythecium salebrosum]]
|-id=key-0-18
|18
|Alar regions small or poorly delimited; sexual condition dioicous or autoicous
|[[#key-0-19| > 19]]
|-id=key-0-18
|18
|Alar regions extensive; sexual condition dioicous
|[[#key-0-23| > 23]]
|-id=key-0-19
|19
|Plants large, rigid; leaves strongly plicate; laminal cell walls thick, especially at base where strongly porose; arctic, alpine.
|[[Brachythecium turgidum|Brachythecium turgidum]]
|-id=key-0-19
|19
|Plants small to large, if large then not rigid; leaves not to somewhat plicate; laminal cell walls moderately thick to moderately thin, not or moderately porose; widespread
|[[#key-0-20| > 20]]
|-id=key-0-20
|20
|Sexual condition autoicous
|[[#key-0-21| > 21]]
|-id=key-0-20
|20
|Sexual condition apparently dioicous (male plants and sporophytes unknown)
|[[#key-0-22| > 22]]
|-id=key-0-21
|21
|Leaves broadly to narrowly ovate-triangular, 0.8-1.2 mm wide; widespread.
|[[Brachythecium acutum|Brachythecium acutum]]
|-id=key-0-21
|21
|Leaves ovate-lanceolate or lanceolate, 0.6-0.8 mm wide; Alaska.
|[[Brachythecium jacuticum|Brachythecium jacuticum]]
|-id=key-0-22
|22
|Alar cells relatively small; alpine belt in Rocky Mountains.
|[[Brachythecium brandegeei|Brachythecium brandegeei]]
|-id=key-0-22
|22
|Alar cells enlarged; Alaska.
|[[Brachythecium udum|Brachythecium udum]]
|-id=key-0-23
|23
|Leaves 1.1-1.5(-1.9) × 0.5-0.7(-0.8) mm, broadly ovate; acumina often as long as base; sw United States.
|[[Brachythecium ruderale|Brachythecium ruderale]]
|-id=key-0-23
|23
|Leaves (1.2-)1.5-2.8 × (0.4-)0.6-1.1 mm, ovate-lanceolate to ovate; acumina markedly shorter than base; widespread
|[[#key-0-24| > 24]]
|-id=key-0-24
|24
|Leaves straight to falcate-secund, strongly plicate.
|[[Brachythecium erythrorrhizon|Brachythecium erythrorrhizon]]
|-id=key-0-24
|24
|Leaves straight or slightly falcate, if falcate, not or moderately plicate
|[[#key-0-25| > 25]]
|-id=key-0-25
|25
|Leaf apices long-acuminate; bases long-decurrent; laminal cells 40-100 (-125) × 5-9 µm.
|[[Brachythecium albicans|Brachythecium albicans]]
|-id=key-0-25
|25
|Leaf apices short to moderately acuminate; bases short-decurrent; laminal cells 30-80(-90) × 6-9 µm
|[[#key-0-26| > 26]]
|-id=key-0-26
|26
|Leaf decurrency cells short-rectangular.
|[[Brachythecium coruscum|Brachythecium coruscum]]
|-id=key-0-26
|26
|Leaf decurrency cells long-rectangular.
|[[Brachythecium erythrorrhizon|Brachythecium erythrorrhizon]]
|}
</div></div><!--

-->{{#Taxon:
name=Brachythecium
|author=Michael S. Ignatov
|authority=Schimper in P. Bruch and W. P. Schimper
|rank=genus
|parent rank=family
|synonyms=Chamberlainia
|basionyms=
|family=Brachytheciaceae
|distribution=Nearly worldwide;high Arctic to tropics.
|reference=ignatov2008a
|publication title=in P. Bruch and W. P. Schimper, Bryol. Europ.
|publication year=1853
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/8f726806613d60c220dc4493de13607dd3150896/coarse_grained_fna_xml/V28/V28_642.xml
|genus=Brachythecium
}}<!--

-->[[Category:Treatment]][[Category:Brachytheciaceae]]