View source for Cenchrus

{{Treatment/ID
|accepted_name=Cenchrus
|accepted_authority=L.
|publications=
|basionyms=
|synonyms=
|hierarchy=Poaceae;Poaceae subfam. Panicoideae;Poaceae tribe Paniceae;Cenchrus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Poaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Poaceae subfam. Panicoideae]]</div><div class="higher-taxon"><small>tribe</small>[[Poaceae tribe Paniceae]]</div><div class="higher-taxon"><small>genus</small>[[Cenchrus]]</div></div>
|volume=Volume 25
|mention_page=
|treatment_page=page 529
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism duration;whole_organism duration;whole_organism growth form"><b>Plants </b>annual or perennial.</span> <span class="statement" id="st-d0_s1" data-properties="culm some measurement;culm orientation;culm orientation;culm shape"><b>Culms </b>5-200 cm, erect or decumbent, usually geniculate;</span> <span class="statement" id="st-d0_s2" data-properties="node pubescence;internode pubescence">nodes and internodes usually glabrous.</span> <span class="statement" id="st-d0_s3" data-properties="sheath architecture;sheath pubescence"><b>Sheaths </b>open, usually glabrous;</span> <span class="statement" id="st-d0_s4" data-properties="ligule texture;ligule architecture or pubescence or shape;cilium length or size">ligules membranous, ciliate, cilia as long as or longer than the basal membrane;</span> <span class="statement" id="st-d0_s5" data-properties="blade shape;blade shape;margin pubescence or texture;margin relief">blades flat or folded, margins cartilaginous, scabridulous.</span> <span class="statement" id="st-d0_s6" data-properties="inflorescence position or structure subtype;branch size"><b>Inflorescences </b>terminal, spikelike panicles of highly reduced branches termed fascicles (burs);</span> <span class="statement" id="st-d0_s7" data-properties="branch panicle shape;branch panicle arrangement;branch panicle arrangement;series quantity;bristle quantity;bristle fragility;bristle fusion;bristle relief;bristle pubescence;bristle shape;bristle position relational;bristle position;bristle quantity">fascicles consisting of 1-2 series of many, stiff, partially fused, usually retrorsely scabridulous to strigose, sharp bristles surrounding, sometimes almost concealing, 1-4 spikelets;</span> <span class="statement" id="st-d0_s8" data-properties="outer bristle presence;outer bristle shape;outer bristle shape">outer (lower) bristles, if present, in 1 or more whorls, terete or flattened;</span> <span class="statement" id="st-d0_s9" data-properties="">inner (upper) bristles usually strongly flattened, fused at least at the base and forming a disk, frequently to more than 1/2 their length and forming a cupule;</span> <span class="statement" id="st-d0_s10" data-properties="inner bristle shape;inner bristle fusion;inner bristle length;inner bristle length">disarticulation at the base of the fascicles.</span> <span class="statement" id="st-d0_s11" data-properties="spikelet architecture;floret quantity"><b>Spikelets </b>sessile, with 2 florets;</span> <span class="statement" id="st-d0_s12" data-properties="lower floret reproduction">lower florets usually sterile;</span> <span class="statement" id="st-d0_s13" data-properties="upper floret reproduction">upper florets bisexual.</span> <span class="statement" id="st-d0_s14" data-properties="lower glume shape;lower glume texture;lower glume pubescence;lower glume architecture;lower glume shape"><b>Lower </b>glumes ovate, scarious, glabrous, 1-veined, acute to acuminate;</span> <span class="statement" id="st-d0_s15" data-properties="upper glume shape;upper glume architecture;upper lower lemma shape;upper lower lemma architecture">upper glumes and lower lemmas ovate, 3-9-veined;</span> <span class="statement" id="st-d0_s16" data-properties="lower palea coloration;lower palea coloration;lemma variability">lower paleas equaling the lemmas, tawny or purplish;</span> <span class="statement" id="st-d0_s17" data-properties="upper lemma size;upper lemma texture;upper lemma shape;upper lemma architecture;upper lemma shape;upper palea size;upper palea texture;upper palea shape;upper palea architecture;upper palea shape">upper lemmas and paleas subequal, indurate, ovate, obscurely veined, acuminate.</span> <span class="statement" id="st-d0_s18" data-properties=""><b>Caryopses </b>obtrulloid.</span> <span class="statement" id="st-d0_s19" data-properties="caryopsis shape;x chromosome quantity">x = 17.</span><!--

-->{{Treatment/Body
|distribution=Ariz.;D.C;Fla.;Miss.;Ohio;Pa.;Puerto Rico;Tex.;Wash.;Va.;W.Va.;Del.;Wis.;N.Mex.;Pacific Islands (Hawaii);Maine;Vt.;Conn.;N.J.;N.Y.;Kans.;N.Dak.;Nebr.;Okla.;S.Dak.;Wyo.;N.C.;N.H.;La.;Colo.;Ala.;Ga.;Tenn.;S.C.;Nev.;Mass.;R.I.;Virgin Islands;Calif.;Oreg.;Ark.;Ill.;Ind.;Iowa;Md.;Utah;Mo.;Minn.;Mich.;Mont.;B.C.;Ont.;Que.;Ky.
|discussion=<p>Cenchrus has about 16, primarily tropical species, most of which are readily (and painfully) recognized by their spiny fascicles. Most of its species differ from those of Pennisetum in having retrorsely scabrous or strigose inner bristles that are fused to well above their bases. The species are generally considered to be undesirable weeds.</p><!--
--><p>Seven species of Cenchrus are native to the Flora region. The eighth species in this treatment was collected once in Westchester County, New York, but does not appear to have become established in the Flora region.</p>
|tables=
|references={{Treatment/Reference
|id=chase1920a
|text=Chase, A. 1920. The North American species of Cenchrus. Contr. U.S. Natl. Herb. 22':45-77
}}{{Treatment/Reference
|id=delisle1963a
|text=DeLisle, D.G. 1963. Taxonomy and distribution of the genus Cenchrus. Iowa State Coll. J. Sci. 37:259-351
}}{{Treatment/Reference
|id=gayle1892a
|text=Gayle, E.E. 1892. The spines of Cenchrus tribuloides L. Bot. Gaz. 17:126-127
}}{{Treatment/Reference
|id=sohns1955b
|text=Sohns, E.R. 1955. Cenchrus and Pennisetum: Fascicle morphology. J. Wash. Acad. Sci. 45:135-143.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|All bristles terete, fused only at the base; fascicles not burlike
|[[Cenchrus myosuroides|Cenchrus myosuroides]]
|-id=key-0-1
|1
|Inner bristles flattened, variously fused, forming a shallow disk or distinct cupule; fascicles burlike.
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Fascicles having 1 whorl of fused, flattened inner bristles, subtended by 5-25 free, terete, outer bristles.
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Inner bristles fused only at the base and forming a shallow disk, their abaxial surfaces with 1-3 grooves
|[[Cenchrus biflorus|Cenchrus biflorus]]
|-id=key-0-3
|3
|Inner bristles fused for 1/3 – 1/2 their length or more, forming a globose cupule, their abaxial surfaces not grooved.
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Rachis internodes 0.8-1.7 mm long; the majority of the outer bristles equaling or slightly exceeding the inner, flattened bristles
|[[Cenchrus brownii|Cenchrus brownii]]
|-id=key-0-4
|4
|Rachis internodes 2-4 mm long; the majority of the outer bristles about 1/2 as long as the inner, flattened bristles
|[[Cenchrus echinatus|Cenchrus echinatus]]
|-id=key-0-2
|2
|Fascicles having more than 1 whorl of flattened inner bristles, these originating at irregular intervals throughout the body of the cupule, sometimes subtended by terete outer bristles.
|[[#key-0-3| > 3]]
|-id=key-0-5
|5
|Plants perennial, long-lived; fascicles not imbricate, usually glabrous; leaf blades 1-3.5 mm wide
|[[Cenchrus gracillimus|Cenchrus gracillimus]]
|-id=key-0-5
|5
|Plants annual or perennial but short-lived; fascicles imbricate, usually pubescent; leaf blades (1)3-14.2 mm wide.
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Inner bristles 0.5-0.9(1.4) mm wide at the base; fascicles with 45-75 bristles
|[[Cenchrus longispinus|Cenchrus longispinus]]
|-id=key-0-6
|6
|Inner bristles 1-3 mm wide at the base; fascicles with 8-43 bristles.
|[[#key-0-7| > 7]]
|-id=key-0-7
|7
|Fascicles densely pubescent, 9-16 mm long, with 1(2) spikelets; inner bristles 4-8 mm long
|[[Cenchrus tribuloides|Cenchrus tribuloides]]
|-id=key-0-7
|7
|Fascicles glabrous or sparsely to moderately pubescent, 5.5-10.2 mm long, with 2-4 spikelets; inner bristles 2-5.8 mm long
|[[Cenchrus spinifex|Cenchrus spinifex]]
|}
</div></div><!--

-->{{#Taxon:
name=Cenchrus
|author=Michael T. Stieber;J.K. Wipff;
|authority=L.
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Poaceae
|distribution=Ariz.;D.C;Fla.;Miss.;Ohio;Pa.;Puerto Rico;Tex.;Wash.;Va.;W.Va.;Del.;Wis.;N.Mex.;Pacific Islands (Hawaii);Maine;Vt.;Conn.;N.J.;N.Y.;Kans.;N.Dak.;Nebr.;Okla.;S.Dak.;Wyo.;N.C.;N.H.;La.;Colo.;Ala.;Ga.;Tenn.;S.C.;Nev.;Mass.;R.I.;Virgin Islands;Calif.;Oreg.;Ark.;Ill.;Ind.;Iowa;Md.;Utah;Mo.;Minn.;Mich.;Mont.;B.C.;Ont.;Que.;Ky.
|reference=chase1920a;delisle1963a;gayle1892a;sohns1955b
|publication title=
|publication year=
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V25/V25_1371.xml
|subfamily=Poaceae subfam. Panicoideae
|tribe=Poaceae tribe Paniceae
|genus=Cenchrus
|blade shape=folded;flat
|branch panicle arrangement=fascicles;fascicles
|branch panicle shape=spikelike
|branch size=reduced
|bristle fragility=stiff
|bristle fusion=fused
|bristle position=concealing
|bristle position relational=surrounding
|bristle pubescence=strigose
|bristle quantity=1;4
|bristle relief=scabridulous
|bristle shape=sharp
|caryopsis shape=obtrulloid
|cilium length or size=longer
|culm orientation=decumbent;erect
|culm shape=geniculate
|culm some measurement=5cm;200cm
|floret quantity=2
|inflorescence position or structure subtype=terminal
|inner bristle fusion=fused
|inner bristle length=/2;1
|inner bristle shape=flattened
|internode pubescence=glabrous
|lemma variability=equaling
|ligule architecture or pubescence or shape=ciliate
|ligule texture=membranous
|lower floret reproduction=sterile
|lower glume architecture=1-veined
|lower glume pubescence=glabrous
|lower glume shape=acute;acuminate
|lower glume texture=scarious
|lower palea coloration=purplish;tawny
|margin pubescence or texture=cartilaginous
|margin relief=scabridulous
|node pubescence=glabrous
|outer bristle presence=absent
|outer bristle shape=flattened;terete
|series quantity=1;2
|sheath architecture=open
|sheath pubescence=glabrous
|spikelet architecture=sessile
|upper floret reproduction=bisexual
|upper glume architecture=3-9-veined
|upper glume shape=ovate
|upper lemma architecture=veined
|upper lemma shape=acuminate;ovate
|upper lemma size=subequal
|upper lemma texture=indurate
|upper lower lemma architecture=3-9-veined
|upper lower lemma shape=ovate
|upper palea architecture=veined
|upper palea shape=acuminate;ovate
|upper palea size=subequal
|upper palea texture=indurate
|whole_organism duration=perennial;annual
|whole_organism growth form=plant
|x chromosome quantity=17
}}<!--

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