View source for Thuidium

{{Treatment/ID
|accepted_name=Thuidium
|accepted_authority=Schimper in P. Bruch and W. P. Schimper
|publications={{Treatment/Publication
|title=in P. Bruch and W. P. Schimper, Bryol. Europ.
|place=5: 157, plates 481 – 486. 1852
|year=1852
}}
|basionyms=
|synonyms=
|hierarchy=Thuidiaceae;Thuidium
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Thuidiaceae]]</div><div class="higher-taxon"><small>genus</small>[[Thuidium]]</div></div>
|etymology=Genus Thuja and Latin -idium, diminutive, alluding to branched habit
|volume=Volume 28
|mention_page=page 345, 374, 375, 377, 378, 648
|treatment_page=page 380
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>large. <b>Stems</b> creeping to arched-ascending, 2- or 3-pinnate; paraphyllia mostly foliose, lanceolate or filiform-branched; axillary hairs 2–6(–7)-celled. <b>Stem</b> leaves ovate; margins plane, reflexed, or revolute, papillose-serrulate proximally, often serrulate distally by projecting cell ends; costa ending before apex; laminal cells rounded- to oblong-hexagonal, rhombic, or elliptic, coarsely 1-papillose abaxially, papillae sometimes 2-fid, appearing multipapillose. <b>Branch</b> leaves ovate; margins incurved, erect, or recurved, entire to denticulate; apex usually acute; costa ending before apex, not covered with cells apically; laminal cells rounded, hexagonal, elliptic, or oblong-rhombic, 1-papillose. <b>Sexual</b> condition dioicous; perichaetial leaves lanceolate or ovate-lanceolate, margins sometimes ciliate, costa ending near apex, laminal cells smooth or somewhat papillose. <b>Seta</b> smooth or rarely papillose. <b>Capsule</b> inclined to horizontal, curved-cylindric, asymmetric; annulus 2–4-seriate; operculum conic or rostrate from convex-conic base; endostome segments not perforate, cilia in groups of 2–4.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico;West Indies;Central America;South America;Europe;Asia.
|discussion=<p>Species ca. 230 (4 in the flora).</p><!--
--><p><i>Thuidium</i> is characterized by abundant, 2- or 3-pinnate paraphyllia; dioicous sexuality; dimorphic stem and branch leaves with short, thick-walled cells that are papillose abaxially and nearly always 1-papillose; stem leaves with base ± plicate and laminal cells ± uniform; apical cells of branch leaves usually truncate and multipapillose; and setae nearly always smooth. The capsule is smooth, with a short neck. The genus is treated here in a sense exclusive of <i>Abietinella</i>, <i>Cyrto-hypnum</i>, and <i>Rauiella</i> (see W. R. Buck and H. A. Crum 1990). <i>Abietinella</i> is relatively robust and has 1-pinnate branching, abundant paraphyllia, dioicous inflorescences, laminal cells 1-papillose on both surfaces, and 3- or 4-celled, brown axillary hairs. <i>Cyrto-hypnum</i> and <i>Rauiella</i> are small with autoicous inflorescences, paraphyllia short and not much branched, and laminal cells papillose on both surfaces (most commonly multipapillose). <i>Cyrto-hypnum</i> has mostly 2-pinnate branching, 2-celled axillary hairs, leaves incurved when dry, laminal cells plane, and setae often roughened. <i>Rauiella</i> has 1-pinnate branching, 3-celled axillary hairs, leaves not incurved when dry, strongly bulging laminal cells, and smooth setae.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems usually 3-pinnate; branch leaf apical cell acute, smooth.
|[[Thuidium tamariscinum|Thuidium tamariscinum]]
|-id=key-0-1
|1
|Stems usually 2-pinnate; branch leaf apical cell truncate, multipapillose
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Stem leaves incurved basally and spreading apically when dry, distinctly plicate; costae nearly filling acumen; paraphyllia papillose at cell ends.
|[[Thuidium recognitum|Thuidium recognitum]]
|-id=key-0-2
|2
|Stem leaves ± erect when dry, not or somewhat plicate; costae not filling acumen; paraphyllia papillose at sides of cells or cell ends
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Stem leaf apices short-pointed; margins plane or sometimes reflexed basally; distal laminal cells appearing 1-3-papillose because papillae 2-fid.
|[[Thuidium alleniorum|Thuidium alleniorum]]
|-id=key-0-3
|3
|Stem leaf apices acuminate; margins revolute throughout; laminal cells coarsely 1-papillose, not appearing multipapillose, papillae sometimes 2-fid.
|[[Thuidium delicatulum|Thuidium delicatulum]]
|}
</div></div><!--

-->{{#Taxon:
name=Thuidium
|author=Howard A. Crum†
|authority=Schimper in P. Bruch and W. P. Schimper
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Thuidiaceae
|distribution=North America;Mexico;West Indies;Central America;South America;Europe;Asia.
|reference=None
|publication title=in P. Bruch and W. P. Schimper, Bryol. Europ.
|publication year=1852
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V28/V28_597.xml
|genus=Thuidium
}}<!--

-->[[Category:Treatment]][[Category:Thuidiaceae]]