View source for ×leydeum ← ×leydeum You do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. {{Treatment/ID |accepted_name=×leydeum |accepted_authority=Barkworth |publications= |basionyms= |synonyms= |hierarchy=Poaceae;Poaceae subfam. Pooideae;Poaceae tribe Triticeae;×leydeum |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Poaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Poaceae subfam. Pooideae]]</div><div class="higher-taxon"><small>tribe</small>[[Poaceae tribe Triticeae]]</div><div class="higher-taxon"><small>genus</small>[[×leydeum]]</div></div> |volume=Volume 24 |mention_page= |treatment_page=page 369 }}<!-- --><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>perennial; rhizomatous, sometimes shortly so. <b>Culms</b> to 140 cm tall, 1-3 mm thick. <b>Spikes</b> 10-15 cm long, 5-12 mm wide excluding the awns, erect, sometimes lax, nodes with 2-3 spikelets; internodes 3-5 mm; disarticulation in the rachises, sometimes delayed. <b>Spikelets</b> appressed, with 1-3 florets. <b>Glumes</b> equal or unequal, 10-25 mm long, 0.2-1.5 mm wide, tapering from below midlength or subulate from the base; lemmas glabrous or hairy, awned, awns 1-10 mm; anthers 1.8-3 mm long, 0.1-0.3 mm thick. <b>Caryopses</b> not developed.</span><!-- -->{{Treatment/Body |distribution=Oreg. |discussion=<p>×Leydeum consists of hybrids between <i>Hordeum</i> and <i>Leymus</i>. The number of named ×Leydeum hybrids is substantially lower than that for hybrids between <i>Hordeum</i> and <i>Elymus</i>.</p><!-- --><p>This probably reflects the lower likelihood of such hybrids being formed, because <i>Leymus</i> does not incorporate the H genome of <i>Hordeum</i>, whereas <i>Elymus</i> does. It is also possible that such hybrids are less likely to be recognized, because inland species of <i>Leymus</i>, like <i>Hordeum</i>, have narrow glumes. Of the three species recognized, two involve the coastal species <i>L. mollis</i>, which has flat glumes; these hybrids have intermediate glumes and rachises that tend to disarticulate. ×Leydeum piperi, the only hybrid involving one of the inland species of <i>Leymus</i>, differs from <i>Leymus</i> in its disarticulating rachises, and from <i>Hordeum</i> in having 2 spikelets per node and 2-3 florets in the larger spikelets.</p> |tables= |references={{Treatment/Reference |id=bowden1967c |text=Bowden, W.M. 1967. Taxonomy of intergeneric hybrids of the tribe Triticeae from North America. Canad. J. Bot. 45:™11-724 }}{{Treatment/Reference |id=covas1949a |text=Covas, G. 1949. Taxonomic observations on the North American species of Hordeum. Madrono 9:233-264 }}{{Treatment/Reference |id=hodgson1965a |text=Hodgson, H.J. and W.W. Mitchell. 1965. A new Elymordeum hybrid from Alaska. Canad. J. Bot 43:1355-1358 }}{{Treatment/Reference |id=hulten1968b |text=Hulten, E. 1968. Comments on the flora of Alaska and Yukon. Ark. Bot., n.s., 7:1-147. }} }}<!-- --><!-- -->{{#Taxon: name=×leydeum |author=Mary E. Barkworth; |authority=Barkworth |rank=genus |parent rank=tribe |synonyms= |basionyms= |family=Poaceae |distribution=Oreg. |reference=bowden1967c;covas1949a;hodgson1965a;hulten1968b |publication title= |publication year= |special status= |source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/200273ad09963decb8fc72550212de541d86569d/coarse_grained_fna_xml/V24/V24_532.xml |subfamily=Poaceae subfam. Pooideae |tribe=Poaceae tribe Triticeae |genus=×leydeum }}<!-- -->[[Category:Treatment]][[Category:Poaceae tribe Triticeae]] Templates used on this page: Template:Poaceae (view source) Template:Treatment/AuthorLink (view source) Template:Treatment/Body (view source) Template:Treatment/Body/Maps (view source) Template:Treatment/ID (view source) Template:Treatment/Reference (view source) Return to ×leydeum.