View source for Echinocactus polycephalus

{{Treatment/ID
|accepted_name=Echinocactus polycephalus
|accepted_authority=Engelmann & J. M. Bigelow
|publications={{Treatment/Publication
|title=Proc. Amer. Acad. Arts
|place=3: 276. 1856
|year=1856
}}
|common_names=Many-headed barrel cactus;cottontop cactus
|basionyms=
|synonyms=
|hierarchy=Cactaceae;Cactaceae subfam. Cactoideae;Echinocactus;Echinocactus polycephalus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Cactaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Cactaceae subfam. Cactoideae]]</div><div class="higher-taxon"><small>genus</small>[[Echinocactus]]</div><div class="higher-taxon"><small>species</small>[[Echinocactus polycephalus]]</div></div>
|volume=Volume 4
|mention_page=page 188
|treatment_page=page 189
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism architecture;whole_organism growth form;mound architecture or arrangement;branch atypical quantity;branch quantity"><b>Plants </b>branched from base (rarely unbranched) forming compact mounds of 2–50 (–130) branches.</span> <span class="statement" id="st-d0_s1" data-properties="stem coloration;stem shape;stem length;stem atypical width;stem width"><b>Stems </b>gray-green to yellow-green, spheric to short cylindric, 15–40 × (9–) 15–30 cm;</span> <span class="statement" id="st-d0_s2" data-properties="rib quantity;rib orientation;rib course;rib crest size;rib crest shape;side prominence or shape">ribs 11–25, usually vertical, or somewhat helically curving around stem, rib crests not constricted between areoles (slightly so when desiccated), sharp, with flat sides.</span> <span class="statement" id="st-d0_s3" data-properties="spine quantity;spine course;spine shape;spine architecture;spine coloration;spine life cycle;spine coloration;spine shape;spine shape;stem trichome pubescence;stem trichome pubescence;stem trichome size;stem trichome coloration;stem trichome architecture"><b>Spines </b>10–19 per areole, straight to curved but not hooked, often twisted, red to straw colored, aging gray, flattened to abaxially ridged, annulate-ridged, nearly obscuring stem surfaces, glabrous to canescent with minute, white, unicellular trichomes often obscuring underlying spine color;</span> <span class="statement" id="st-d0_s4" data-properties="spine arrangement;spine quantity">radial spines 6–14 per areole;</span> <span class="statement" id="st-d0_s5" data-properties="central spine quantity;abaxial spine length;abaxial spine course;abaxial spine orientation">central spines 4, abaxial frequently longest, straight to somewhat recurved.</span> <span class="statement" id="st-d0_s6" data-properties="flower length;flower width;flower width"><b>Flowers </b>5.5–5.8 × 4–6 cm, narrower when spines restrict flower from opening fully;</span> <span class="statement" id="st-d0_s7" data-properties="inner tepal coloration;inner tepal coloration;inner tepal some measurement;inner tepal shape">inner tepals bright-yellow, color uniform from base to apex, 24–26 mm, sparsely, minutely toothed;</span> <span class="statement" id="st-d0_s8" data-properties="stigma lobe coloration">stigma lobes bright-yellow.</span> <span class="statement" id="st-d0_s9" data-properties="fruit dehiscence;fruit shape;pore position;pore life cycle;surface prominence;surface condition;shell coloration;shell some measurement"><b>Fruits </b>dehiscent through basal abscission pore, ovoid, surfaces largely hidden by hairs in axils of scales and long areolar trichomes of stem apex, usually drying to tan shell before seed dispersal, 15–40 mm;</span> <span class="statement" id="st-d0_s10" data-properties="scale quantity;scale coloration;scale coloration;scale prominence or shape;midstripe coloration;tip shape;tip pubescence;tip pubescence">scales abundant, yellow to reddish throughout, or yellow with reddish midstripes, flat, tips spinelike, glabrous or canescent.</span> <span class="statement" id="st-d0_s11" data-properties="seed coloration;seed shape;seed shape;seed some measurement;seed architecture or pubescence or relief;seed reflectance;seed pubescence or relief or texture;seed reflectance;surface prominence"><b>Seeds </b>dark maroon to black, ± obovoid-reniform or comma-shaped, 2.4–4.7 mm, smooth and shiny or granular and dull from protruding surfaces of testa cells;</span> <span class="statement" id="st-d0_s12" data-properties="cell surface shape">testa cell surfaces sometimes hemispheric to hexagonally faceted.</span><!--

-->{{Treatment/Body
|distribution=Ariz.;Calif.;Nev.;Mexico
|discussion=<p>Varieties 2 (2 in the flora).</p><!--
--><p>The varieties of Echinocactus polycephalus are distinguishable by several morphologic characteristics. Plants morphologically intermediate between the two varieties, however, occur at one site south of Lake Mead, Arizona, where the geographic ranges of the varieties are contiguous, but ecologically segregated.</p><!--
--><p>Although Echinocactus polycephalus var. polycephalus and var. xeranthemoides have been reported for southern Utah (L. D. Benson 1982; D. J. Ferguson 1992; G. Unger 1992), M. Chamberland (1995, 1997) found neither populations nor herbarium specimens from the past 100 years.</p>
|tables=
|references={{Treatment/Reference
|id=chamberland1997a
|text=Chamberland, M. 1997. Systematics of the Echinocactus polycephalus complex (Cactaceae). Syst. Bot. 22: 303–313.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Scales of fruit 10-14 mm, reddish to maroon, aging tan to black, not protruding beyond dried perianth parts on fruit; seed papillate-roughened (exposed surfaces of testa cells protruding, hemispheric to hexagonally faceted, appearing dull except for the microscopically sparkling individual facets)
|[[Echinocactus polycephalus var. polycepha|Echinocactus polycephalus var. polycepha]]
|-id=key-0-1
|1
|Scales of fruit 16-30 mm, reddish, tan, or yellow, aging yellow, usually protruding beyond dried perianth parts on fruit; seed smooth (exposed surfaces of testa cells flat or slightly convex, surfaces uniformly shiny)
|[[Echinocactus polycephalus var. xeranthem|Echinocactus polycephalus var. xeranthem]]
|}
</div></div><!--

-->{{#Taxon:
name=Echinocactus polycephalus
|authority=Engelmann & J. M. Bigelow
|rank=species
|parent rank=genus
|synonyms=
|basionyms=
|family=Cactaceae
|distribution=Ariz.;Calif.;Nev.;Mexico
|reference=chamberland1997a
|publication title=Proc. Amer. Acad. Arts
|publication year=1856
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V4/V4_355.xml
|subfamily=Cactaceae subfam. Cactoideae
|genus=Echinocactus
|species=Echinocactus polycephalus
|abaxial spine course=straight
|abaxial spine length=longest
|abaxial spine orientation=recurved
|branch atypical quantity=50;130
|branch quantity=2;50
|cell surface shape=hemispheric;hexagonally faceted
|central spine quantity=4
|flower length=5.5cm;5.8cm
|flower width=narrower;4cm;6cm
|fruit dehiscence=dehiscent
|fruit shape=ovoid
|inner tepal coloration=uniform;bright-yellow
|inner tepal shape=toothed
|inner tepal some measurement=24mm;26mm
|midstripe coloration=reddish
|mound architecture or arrangement=compact
|pore life cycle=abscission
|pore position=basal
|rib course=curving
|rib crest shape=sharp
|rib crest size=not constricted
|rib orientation=vertical
|rib quantity=11;25
|scale coloration=yellow;yellow;reddish
|scale prominence or shape=flat
|scale quantity=abundant
|seed architecture or pubescence or relief=smooth
|seed coloration=dark maroon;black
|seed pubescence or relief or texture=granular
|seed reflectance=dull;shiny
|seed shape=comma--shaped;obovoid-reniform
|seed some measurement=2.4mm;4.7mm
|shell coloration=tan
|shell some measurement=15mm;40mm
|side prominence or shape=flat
|spine architecture=twisted
|spine arrangement=radial
|spine coloration=gray;red;straw colored
|spine course=straight;curved
|spine life cycle=aging
|spine quantity=6;14
|spine shape=annulate-ridged;flattened;abaxially ridged
|stem atypical width=9cm;15cm
|stem coloration=gray-green;yellow-green
|stem length=15cm;40cm
|stem shape=spheric;short cylindric
|stem trichome architecture=unicellular
|stem trichome coloration=white
|stem trichome pubescence=canescent;glabrous
|stem trichome size=minute
|stem width=15cm;30cm
|stigma lobe coloration=bright-yellow
|surface condition=drying
|surface prominence=protruding;hidden
|tip pubescence=canescent;glabrous
|tip shape=spinelike
|whole_organism architecture=branched
|whole_organism growth form=plant
}}<!--

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