View source for Didymodon perobtusus

{{Treatment/ID
|accepted_name=Didymodon perobtusus
|accepted_authority=Brotherus
|publications={{Treatment/Publication
|title=Rev. Bryol.
|place=56: 1. 1928,
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Barbula perobtusa
|authority=(Brotherus) P. C. Chen
|rank=species
}}
|hierarchy=Pottiaceae;Pottiaceae subfam. Barbuloideae;Didymodon;Didymodon perobtusus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Pottiaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Pottiaceae subfam. Barbuloideae]]</div><div class="higher-taxon"><small>genus</small>[[Didymodon]]</div><div class="higher-taxon"><small>species</small>[[Didymodon perobtusus]]</div></div>
|volume=Volume 27
|mention_page=page 541, 542, 548
|treatment_page=page 549
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism coloration;whole_organism coloration;whole_organism coloration;whole_organism growth form"><b>Plants </b>usually green, red or dark-brown.</span> <span class="statement" id="st-d0_s1" data-properties="stem some measurement;central strand presence"><b>Stems </b>to 0.6 cm, central strand present.</span> <span class="statement" id="st-d0_s2" data-properties="leaf-stem orientation;leaf-stem orientation;leaf-stem shape;leaf-stem architecture;leaf-stem shape;leaf-stem shape;leaf-stem distance;base shape;base shape;margin orientation;margin shape;apex shape;apex shape"><b>Stem-</b>leaves appressed-incurved when dry, weakly spreading and not keeled when moist, monomorphic, ovatelanceolate, broadly concave adaxially across leaf, usually 0.7–1.2 mm, base weakly differentiated in shape, ovate, margins weakly recurved at mid leaf, minutely crenulate, apex rounded-acute, often weakly cucullate;</span> <span class="statement" id="st-d0_s3" data-properties="costa architecture or shape;costa shape;cell atypical quantity;cell quantity;adaxial costal cell shape;adaxial costal cell height or length or size;adaxial costal cell shape;adaxial costal cell quantity;cell width;mid leaf quantity;layer quantity">costa ending (2–) 4–6 cells below the apex, not strongly spurred, little tapering, without an adaxial pad of cells, adaxial costal cells quadrate or short to long-rectangular, 2 cells wide at mid leaf often grading to 4 proximally, guide cells in 1 layer;</span> <span class="statement" id="st-d0_s4" data-properties="basal laminal cell variability;wall width;wall width;wall shape;wall architecture">basal laminal cells differentiated medially, walls thin or thick, quadrate to rectangular, not perforated;</span> <span class="statement" id="st-d0_s5" data-properties="distal laminal cell width;distal laminal cell quantity;distal laminal cell quantity;papilla presence;papilla prominence;papilla position;papilla architecture;papilla quantity;lumen shape;lumen architecture or course">distal laminal cells 9–11 wide, 1: 1, papillae absent visible or low, simple, 1 over each lumen, lumens subquadrate to irregular, walls evenly thickened, weakly convex on both sides of lamina, 1-stratose.</span> <span class="statement" id="st-d0_s6" data-properties="gemma reproduction;gemma architecture"><b>Specialized </b>asexual reproduction by mostly unicellular gemmae in leaf-axils.</span> <span class="statement" id="st-d0_s7" data-properties="wall size or width;wall shape;wall architecture;wall development;wall reproduction"><b>Sexual </b>condition only perichaetial plants seen.</span> <span class="statement" id="st-d0_s8" data-properties=""><b>Sporophytes </b>unknown.</span> <span class="statement" id="st-d0_s9" data-properties="sporophyte position or shape;sporophyte structure in adjective form;sporophyte coloration"><b>Distal </b>laminal KOH reaction red.</span><!--

-->{{Treatment/Body
|habitat=Calcareous rock or soil, bluffs, often near waterfalls
|elevation=low to high elevations (100-3000 m)
|distribution=N.W.T.;Yukon;e Asia
|discussion=<p>Didymodon perobtusus is an extremely rare species known in the flora area from only two stations: Northwest Territories, Mackenzie District, Nahanni National Park, Virginia Falls, Scotter 22433 (NY); and Yukon, Firth River basin, near mouth of Mancha Creek, 68°40’N, 141°W, Sharp MC-58152a pro parte, 1958 (NY). It has several characters in common with D. revolutus of the southwestern United States and Mexico, including leaf and laminal papillae shape and unicellular gemmae borne in dense axillary clusters; however, D. revolutus differs by the strongly recurved to revolute margins, leaf cells with thin, light yellow walls, and gemmiferous plants uncommon, the propagula all unicellular. Both North American collections seen were from stations at which D. subandreaeoides is also present, growing in separate or occasionally confluent cushions. The taxonomic position of D. perobtusus is not clear. It is here placed near D. subandreaeoides because of dark, reddish color and similarity of areolation and laminal papillae. It may, however, turn out to be related to D. tophaceus, with which it has a certain resemblance.</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Didymodon perobtusus
|authority=Brotherus
|rank=species
|parent rank=genus
|synonyms=Barbula perobtusa
|basionyms=
|family=Pottiaceae
|habitat=Calcareous rock or soil, bluffs, often near waterfalls
|elevation=low to high elevations (100-3000 m)
|distribution=N.W.T.;Yukon;e Asia
|reference=None
|publication title=Rev. Bryol.
|publication year=
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V27/V27_788.xml
|subfamily=Pottiaceae subfam. Barbuloideae
|genus=Didymodon
|species=Didymodon perobtusus
|adaxial costal cell height or length or size=short
|adaxial costal cell quantity=2
|adaxial costal cell shape=long-rectangular;quadrate
|apex shape=cucullate;rounded-acute
|basal laminal cell variability=differentiated
|base shape=ovate;differentiated
|cell atypical quantity=2;4
|cell quantity=4;6
|cell width=wide
|central strand presence=absent
|costa architecture or shape=spurred
|costa shape=tapering
|distal laminal cell quantity=1;1
|distal laminal cell width=9;11
|gemma architecture=unicellular
|gemma reproduction=asexual
|layer quantity=1
|leaf-stem architecture=monomorphic
|leaf-stem distance=0.7mm;1.2mm
|leaf-stem orientation=spreading;appressed-incurved
|leaf-stem shape=concave;ovatelanceolate;keeled
|lumen architecture or course=irregular
|lumen shape=subquadrate
|margin orientation=recurved
|margin shape=crenulate
|mid leaf quantity=0;4
|papilla architecture=simple
|papilla position=low
|papilla presence=absent
|papilla prominence=visible
|papilla quantity=1
|sporophyte coloration=red
|sporophyte position or shape=distal
|sporophyte structure in adjective form=laminal
|stem some measurement=0cm;0.6cm
|wall architecture=1-stratose;not perforated
|wall development=specialized
|wall reproduction=sexual
|wall shape=convex;quadrate;rectangular
|wall size or width=thickened
|wall width=thick;thin
|whole_organism coloration=dark-brown;red;green
|whole_organism growth form=plant
}}<!--

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