View source for Tridens ← Tridens 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=Tridens |accepted_authority=Roem. & Schult. |publications= |basionyms= |synonyms= |hierarchy=Poaceae;Poaceae subfam. Chloridoideae;Poaceae tribe Cynodonteae;Tridens |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Poaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Poaceae subfam. Chloridoideae]]</div><div class="higher-taxon"><small>tribe</small>[[Poaceae tribe Cynodonteae]]</div><div class="higher-taxon"><small>genus</small>[[Tridens]]</div></div> |volume=Volume 25 |mention_page= |treatment_page=page 33 }}<!-- --><span class="statement" id="st-d0_s0" data-properties=""><b>Plants </b>perennial;</span> <span class="statement" id="st-d0_s1" data-properties="whole_organism duration;whole_organism growth form;whole_organism growth form;rhizome height or length or size;rhizome shape;rhizome shape;rhizome architecture">usually cespitose, often with short, knotty rhizomes, occasionally with elongate rhizomes, never stoloniferous.</span> <span class="statement" id="st-d0_s2" data-properties="culm some measurement;culm orientation;culm pubescence"><b>Culms </b>5-180 cm, erect, mostly glabrous, lower nodes sometimes with hairs.</span> <span class="statement" id="st-d0_s3" data-properties="sheath height or length or size;sheath architecture"><b>Sheaths </b>shorter than the internodes, open;</span> <span class="statement" id="st-d0_s4" data-properties="ligule texture;ligule architecture or pubescence or shape;ligule architecture or pubescence or shape">ligules membranous and ciliate or of hairs;</span> <span class="statement" id="st-d0_s5" data-properties="blade length;blade width;blade shape;blade shape;margin width;margin pubescence or texture">blades 6-25 cm long, 1-8 mm wide, flat or involute, margins not thick and cartilaginous.</span> <span class="statement" id="st-d0_s6" data-properties="inflorescence position or structure subtype;inflorescence some measurement;inflorescence position"><b>Inflorescences </b>terminal, usually panicles (sometimes reduced to racemes), 5-40 cm, exceeding the upper leaves, exserted.</span> <span class="statement" id="st-d0_s7" data-properties="spikelet atypical some measurement;spikelet some measurement;spikelet shape;floret atypical quantity;floret quantity;floret quantity;floret reproduction"><b>Spikelets </b>4-10 (13) mm, laterally compressed, with 4-11 (16) florets, more than 1 floret bisexual;</span> <span class="statement" id="st-d0_s8" data-properties="spikelet reproduction">sterile florets distal to the fertile spikelets;</span> <span class="statement" id="st-d0_s9" data-properties="floret reproduction;floret position or shape">disarticulation above the glumes.</span> <span class="statement" id="st-d0_s10" data-properties="distal floret height or length or size;distal floret variability;distal floret height or length or size;distal floret variability"><b>Glumes </b>from shorter than to equaling the distal florets;</span> <span class="statement" id="st-d0_s11" data-properties="lower glume architecture">lower glumes 1 (3) -veined;</span> <span class="statement" id="st-d0_s12" data-properties="upper glume height or length or size;upper glume architecture;lower glume variability">upper glumes shorter than or about equal to the lower glumes, 1-3 (9) -veined, unawned;</span> <span class="statement" id="st-d0_s13" data-properties="callus pubescence;callus pubescence">calluses usually glabrous, sometimes pilose;</span> <span class="statement" id="st-d0_s14" data-properties="lemma coloration;lemma texture;lemma architecture;vein pubescence;apex shape;apex shape or architecture;midvein architecture;midvein some measurement;lateral-vein architecture">lemmas hyaline or membranous, 3-veined, veins usually shortly hairy below, apices rounded to truncate, emarginate to bilobed, midvein often excurrent to 0.5 mm, lateral-veins not or more shortly excurrent;</span> <span class="statement" id="st-d0_s15" data-properties="palea pubescence;palea pubescence;vein pubescence;vein pubescence">paleas glabrous or shortly pubescent on the lower back and margins, veins glabrous or ciliolate;</span> <span class="statement" id="st-d0_s16" data-properties="lodicule quantity;lodicule fusion;lodicule fusion">lodicules 2, free or adnate to the palea;</span> <span class="statement" id="st-d0_s17" data-properties="anther quantity;anther coloration or density">anthers 3, reddish-purple.</span> <span class="statement" id="st-d0_s18" data-properties="caryopsis shape;caryopsis shape;caryopsis coloration"><b>Caryopses </b>dorsiventrally compressed and reniform in cross-section, dark-brown;</span> <span class="statement" id="st-d0_s19" data-properties="">embryos about 2/5 as long as the caryopses.</span> <span class="statement" id="st-d0_s20" data-properties="embryo quantity;x chromosome quantity">x = 10.</span><!-- -->{{Treatment/Body |distribution=Conn.;N.J.;N.Y.;D.C;Del.;Ill.;Ind.;Kans.;Mich.;Minn.;Nebr.;N.Mex.;Nev.;Ohio;Okla.;Wis.;W.Va.;Ont.;Fla.;N.H.;Ariz.;Tex.;La.;N.C.;Tenn.;S.C.;Pa.;Ala.;Calif.;Va.;Colo.;Md.;Mass.;R.I.;Vt.;Ark.;Ga.;Iowa;Utah;Mo.;Miss.;Ky. |discussion=<p>Tridens, a genus of 14 species, is native to the Americas; all ten species described here are native to the the Flora region. Hitchcock (1951) included both Erioneuron and Dasyochloa in Tridens; Tateoka (1961) demonstrated that they should be excluded. One of the differences between Tridens and the other two genera lies in their chromosome bases numbers, 10 in Tridens and 8 in Erioneuron and Dasyochloa. Tridens albescens is exceptional within Tridens in having chromosome numbers that suggest two base numbers, 10 and 8.</p> |tables= |references={{Treatment/Reference |id=burbidge1953a |text=Burbidge, N.T. 1953. The genus Triodia R. Br. (Gramineae). Austral. J. Bot. 1:121-184 }}{{Treatment/Reference |id=gould1975c |text=Gould, F.W. 1975. The grasses of Texas. Texas A&M University Press, College Station, Texas, U.S.A. 653 pp. }}{{Treatment/Reference |id=hitchcock1951d |text=Hitchcock, A.S. 1951 [title page 1950]. Manual of the Grasses of the United States, ed. 2, rev. A. Chase. U.S.D.A. Miscellaneous Publication No. 200. U.S. Government Printing Office, Washington, D.C., U.S.A. 1051 pp. }}{{Treatment/Reference |id=tateoka1961a |text=Tateoka, T. 1961. A biosystematic study of Tridens (Gramineae). Amer. J. Bot. 48:565-573. }} }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Primary panicle branches appressed to strongly ascending; panicles 0.3-4 cm wide, dense and spikelike. |[[#key-0-2| > 2]] |-id=key-0-2 |2 |Lateral veins of the lemmas glabrous or pubescent only at the base |[[Tridens albescens|Tridens albescens]] |-id=key-0-2 |2 |Lateral veins of the lemmas pilose to well above the base. |[[#key-0-3| > 3]] |-id=key-0-3 |3 |Glumes evidently longer than the adjacent lemmas, often twice as long, usually equaling or exceeding the distal florets |[[Tridens strictus|Tridens strictus]] |-id=key-0-3 |3 |Glumes from shorter than to equaling the adjacent lemmas, often exceeded by the distal florets. |[[#key-0-4| > 4]] |-id=key-0-4 |4 |All 3 lemma veins shortly excurrent; calluses pilose |[[Tridens carolinianus|Tridens carolinianus]] |-id=key-0-4 |4 |Lateral lemma veins not excurrent, often terminating before the distal margin, the midvein sometimes excurrent; calluses glabrous or shortly pilose. |[[#key-0-5| > 5]] |-id=key-0-5 |5 |Panicles 7-25 cm long, 0.3-0.8 cm wide; lemma midveins rarely excurrent |[[Tridens muticus|Tridens muticus]] |-id=key-0-5 |5 |Panicles 5-8(10) cm long, 1.2-2.5 cm wide; lemma midveins always shortly excurrent |[[Tridenscongestus|Tridenscongestus]] |-id=key-0-1 |1 |Primary panicle branches ascending to reflexed or drooping; panicles 1-20 cm wide, open, not spikelike. |[[#key-0-2| > 2]] |-id=key-0-6 |6 |All pedicels shorter than 1 mm |[[Tridens ambiguus|Tridens ambiguus]] |-id=key-0-6 |6 |Some pedicels longer than 1 mm. |[[#key-0-7| > 7]] |-id=key-0-7 |7 |Lateral veins of the lemmas rarely excurrent. |[[#key-0-8| > 8]] |-id=key-0-8 |8 |Lemmas 4-6 mm; ligules 0.4-1 mm |[[Tridens buckleyanus|Tridens buckleyanus]] |-id=key-0-8 |8 |Lemmas 2-3.2 mm; ligules 1.2-3 mm |[[Tridens eragrostoides|Tridens eragrostoides]] |-id=key-0-7 |7 |Lateral veins of the lemmas commonly excurrent as short points. |[[#key-0-8| > 8]] |-id=key-0-9 |9 |Blades 1-5 mm wide; panicles 5-16 cm long |[[Tridens texanus|Tridens texanus]] |-id=key-0-9 |9 |Blades mostly 3-10 mm wide; panicles 15-40 cm long |[[Tridens flavus|Tridens flavus]] |} </div></div><!-- -->{{#Taxon: name=Tridens |author=Jesus Valdes-Reyna; |authority=Roem. & Schult. |rank=genus |parent rank=tribe |synonyms= |basionyms= |family=Poaceae |distribution=Conn.;N.J.;N.Y.;D.C;Del.;Ill.;Ind.;Kans.;Mich.;Minn.;Nebr.;N.Mex.;Nev.;Ohio;Okla.;Wis.;W.Va.;Ont.;Fla.;N.H.;Ariz.;Tex.;La.;N.C.;Tenn.;S.C.;Pa.;Ala.;Calif.;Va.;Colo.;Md.;Mass.;R.I.;Vt.;Ark.;Ga.;Iowa;Utah;Mo.;Miss.;Ky. |reference=burbidge1953a;gould1975c;hitchcock1951d;tateoka1961a |publication title= |publication year= |special status= |source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V25/V25_47.xml |subfamily=Poaceae subfam. Chloridoideae |tribe=Poaceae tribe Cynodonteae |genus=Tridens |anther coloration or density=reddish-purple |anther quantity=3 |apex shape=rounded to truncate |apex shape or architecture=emarginate to bilobed |blade length=6cm;25cm |blade shape=involute;flat |blade width=1mm;8mm |callus pubescence=pilose;glabrous |caryopsis coloration=dark-brown |caryopsis shape=reniform;compressed |culm orientation=erect |culm pubescence=glabrous |culm some measurement=5cm;180cm |distal floret height or length or size=shorter;shorter |distal floret variability=equaling;equaling |embryo quantity=2/5 |floret atypical quantity=16 |floret position or shape=distal |floret quantity=4;11 |floret reproduction=sterile;bisexual |inflorescence position=exserted |inflorescence position or structure subtype=terminal |inflorescence some measurement=5cm;40cm |lateral-vein architecture=excurrent |lemma architecture=3-veined |lemma coloration=hyaline |lemma texture=membranous |ligule architecture or pubescence or shape=of hairs;ciliate |ligule texture=membranous |lodicule fusion=adnate;free |lodicule quantity=2 |lower glume architecture=1(3)-veined |lower glume variability=equal |margin pubescence or texture=cartilaginous |margin width=not thick |midvein architecture=excurrent |midvein some measurement=0mm;0.5mm |palea pubescence=pubescent;glabrous |rhizome architecture=stoloniferous |rhizome height or length or size=short |rhizome shape=elongate;knotty |sheath architecture=open |sheath height or length or size=shorter |spikelet atypical some measurement=13 |spikelet reproduction=fertile |spikelet shape=compressed |spikelet some measurement=4mm;10mm |upper glume architecture=1-3(9)-veined |upper glume height or length or size=shorter |vein pubescence=ciliolate;glabrous;hairy |whole_organism duration=perennial |whole_organism growth form=plant;cespitose |x chromosome quantity=10 }}<!-- -->[[Category:Treatment]][[Category:Poaceae tribe Cynodonteae]] 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 Tridens.