View source for Mentzelia

{{Treatment/ID
|accepted_name=Mentzelia
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=1: 516. 1753
|year=1753
}}
|common_names=Blazingstar;stickleaf
|basionyms=
|synonyms=
|hierarchy=Loasaceae;Mentzelia
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Loasaceae]]</div><div class="higher-taxon"><small>genus</small>[[Mentzelia]]</div></div>
|etymology=For Christian Mentzel, 1622–1701, German botanist
|volume=Volume 12
|mention_page=page 492, 497, 498, 519
|treatment_page=page 496
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism duration;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism growth form;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism growth form"><b>Herbs </b>or subshrubs [shrubs or trees], annual, biennial, or perennial;</span> <span class="statement" id="st-d0_s1" data-properties="trichome atypical quantity;trichome shape;trichome architecture or shape;trichome atypical quantity;trichome architecture or shape;surface architecture or pubescence or relief">trichomes (1) pointed with surfaces ± smooth or antrorsely barbed and (2) retrorsely barbed along shaft and at apex or only at apex.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem orientation;stem orientation;stem orientation;stem orientation"><b>Stems </b>erect, clambering, or decumbent.</span> <span class="statement" id="st-d0_s3" data-properties="leaf position;leaf position;leaf position"><b>Leaves </b>basal and cauline or cauline;</span> <span class="statement" id="st-d0_s4" data-properties="petiole presence;petiole presence">petiole present or absent;</span> <span class="statement" id="st-d0_s5" data-properties="blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;margin architecture or shape;margin shape;margin shape;margin shape;margin shape;margin shape">blade hastate, deltate, cordate, ovate, elliptic, lanceolate, linear, spatulate, oblanceolate, obovate, or orbiculate, lobed or unlobed, margins dentate, serrate, crenate, or entire.</span> <span class="statement" id="st-d0_s6" data-properties="inflorescences dichasium architecture or arrangement or growth form;inflorescences flower architecture or arrangement or growth form"><b>Inflorescences </b>dichasia or flowers solitary;</span> <span class="statement" id="st-d0_s7" data-properties="peduncle prominence">peduncle inconspicuous.</span> <span class="statement" id="st-d0_s8" data-properties="pedicel length"><b>Pedicels </b>not elongating in fruit.</span> <span class="statement" id="st-d0_s9" data-properties="hypanthium fusion;hypanthium fusion"><b>Flowers:</b> hypanthium adnate to ovary proximally, free distally;</span> <span class="statement" id="st-d0_s10" data-properties="perianth whorl variability">perianth whorls differentiated;</span> <span class="statement" id="st-d0_s11" data-properties="sepal coloration;sepal fusion;sepal shape;sepal height or length or size">sepals green, connate basally, lanceolate to narrowly ovate, shorter than petals;</span> <span class="statement" id="st-d0_s12" data-properties="petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal fusion;petal fusion;petal shape;petal shape;petal shape;petal shape;petal shape;petal shape;petal shape;petal orientation;petal pubescence;petal pubescence">petals white, yellow, or orange, sometimes red proximally, distinct or connate basally, spatulate, ovate, elliptic, oblanceolate, or obovate, spreading to erect, glabrous or hairy abaxially, on margins, or on apices;</span> <span class="statement" id="st-d0_s13" data-properties="nectary position or shape">nectary distal on ovary;</span> <span class="statement" id="st-d0_s14" data-properties="stamen quantity;stamen position;stamen position">stamens 8–45+, exserted or included;</span> <span class="statement" id="st-d0_s15" data-properties="all architecture;all shape;all shape;all arrangement or course or shape;all architecture;all position;all shape;all arrangement or course or shape;all shape;all shape;all shape;all shape;all shape;inner stamen shape;inner stamen shape;inner stamen arrangement or course or shape;inner stamen length or size">filaments monomorphic, filiform or dorsiventrally flattened and linear, or heteromorphic, outer dorsiventrally flattened and linear, elliptic, spatulate, or oblanceolate [lanceolate], inner filiform or dorsiventrally flattened and linear, longer than anthers;</span> <span class="statement" id="st-d0_s16" data-properties="">anthers without distal connective extension;</span> <span class="statement" id="st-d0_s17" data-properties="staminode presence;staminode presence">staminodes present or absent;</span> <span class="statement" id="st-d0_s18" data-properties="pistil architecture;placenta arrangement">pistil 3-carpellate (5–7-carpellate in M. decapetala), placentae parietal;</span> <span class="statement" id="st-d0_s19" data-properties="stigma shape;stigma shape;stigma relief">stigma lingulate, 3-lobed (5–7-lobed in M. decapetala), papillate.</span> <span class="statement" id="st-d0_s20" data-properties="fruits capsule dehiscence;fruits capsule shape;fruits capsule shape;fruits capsule shape;fruits capsule shape;fruits capsule shape;fruits capsule shape;fruits capsule shape;fruits capsule course;fruits capsule course;fruits capsule shape"><b>Fruits </b>capsules, dehiscing by apical valves [splitting longitudinally], cupshaped, lingulate, subcylindric, cylindric, ovoid, urceolate, clavate, or funnelform, straight or curved, sometimes S-shaped;</span> <span class="statement" id="st-d0_s21" data-properties="sepal duration">sepals persistent.</span> <span class="statement" id="st-d0_s22" data-properties=""><b>Seeds </b>(1–) 2–60+, ovoid, oblong, bottle-shaped, pyriform, irregularly polygonal, or trigonal prisms, dorsiventrally flattened or not, 0.5–4.5 mm, winged or not winged.</span> <span class="statement" id="st-d0_s23" data-properties="seed atypical quantity;seed quantity;seed shape;seed shape;seed shape;seed shape;seed shape;seed shape;seed shape;seed some measurement;seed architecture;seed architecture;x chromosome quantity">x = 9.</span><!--

-->{{Treatment/Body
|distribution=w;c;se North America;Mexico;West Indies;Central America;South America
|discussion=<p>Species ca. 95 (85 in the flora).</p><!--
--><p>Mentzelia is monophyletic and sister to subfam. Gronovioideae (M. L. Moody et al. 2001; L. Hufford et al. 2003). These studies recovered clades that correspond to the six described sections of Mentzelia, including the five treated here and the monospecific sect. Dendromentzelia Urban & Gilg, which consists only of M. arborescens Urban & Gilg of Michoacán and Oaxaca, Mexico.</p><!--
--><p>Mentzelias in North America often are ruderal or found in low-productivity, disturbance-prone environments, such as arroyos, sand dunes, cliffs, or talus slopes. They frequently are associated with distinctive substrates, including gypsum, limestone, serpentine, or volcanic tuff, and some might be edaphically restricted (J. B. Glad 1976; H. J. Thompson and A. M. Powell 1981; C. M. Christy 1997; N. H. Holmgren and P. K. Holmgren 2002; Brokaw et al. 2015).</p><!--
--><p>Changes in chromosome number, through both aneuploidy and polyploidy, have been important in the evolution of Mentzelia. Aneuploidy has been especially important in reproductive isolation in sections Bartonia (haploid chromosome numbers include 9, 10, 11, and 18) and Bicuspidaria (haploid chromosome numbers include 9, 10). In contrast, aneuploidy has not been found in sections Mentzelia or Trachyphytum, although polyploidy has been found in both. In sect. Mentzelia, polyploidy has been reported only in M. asperula. Polyploidy has played a more important role in reproductive isolation and diversification in sect. Trachyphytum, in which diploids, tetraploids, hexaploids, and octoploids have been reported (H. J. Thompson and H. Lewis 1953).</p><!--
--><p>Floral forms differ among the sections of Mentzelia, which may be indicative of reproductive shifts that were important in the differentiation of the sectional lineages. Reproductive ecology has been investigated best in sect. Bicuspidaria, in which Xeralictus bicuspidariae, a robust oligolectic bee, is the main pollinator of M. hirsutissima, M. tricuspis, M. tridentata, and is one of three main pollinators of M. involucrata (G. S. Daniels 1970). Only M. reflexa, which has markedly different flowers compared to other species of sect. Bicuspidaria, is not pollinated by X. bicuspidariae. Instead, another oligolectic bee, Perdita koebelei, is its primary pollinator (Daniels). Bees have been suggested to be the primary pollinators of other sections of Mentzelia, except for the few large-flowered species of sect. Bartonia in which hawk moth pollination has been observed (H. J. Thompson 1960; A. R. Moldenke 1976; R. J. Hill 1977). Many polyploid species of sect. Trachyphytum have small flowers and reportedly self-fertilize (J. E. Zavortink 1966).</p><!--
--><p>Seed surface features are important in Mentzelia taxonomy. In sections Dendromentzelia, Mentzelia, and Micromentzelia, which compose a basal grade in Mentzelia, seed coat cells are longer than wide. In contrast the derived clade consisting of sections Bartonia, Bicuspidaria, and Trachyphytum has seed coat cells that are polygonal and largely isodiametric. The shapes of anticlinal and outer periclinal walls of seed coat cells are similar in sections Bicuspidaria and Trachyphytum but differ among the other sections of North American species. Seed coat cell anticlinal wall shape, which is particularly useful in distinguishing species in sect. Bartonia, may be straight, wavy (curves along walls forming less than 45° angles), or sinuous (curves along walls forming at least 45° angles, often forming U-shaped undulations).</p><!--
--><p>Leaf and bract margins in Mentzelia usually are toothed or lobed to some degree, ranging from serrate or dentate (divided relatively shallowly) through pinnate (defined here as divided partway to the midvein) to pinnatisect (divided nearly or to the midvein).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stamen filaments all or mostly distally 2-lobed.
|[[Mentzelia sect. Bicuspidaria|Mentzelia sect. Bicuspidaria]]
|-id=key-0-1
|1
|Stamen filaments unlobed, or 5 outermost distally 2-lobed and 5–15 inner filaments unlobed (Mentzelia micrantha, sect. Trachyphytum).
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Stamen filaments dorsiventrally flattened, 1–3(–5) outermost petaloid; seeds not winged.
|[[Mentzelia sect. Bicuspidaria|Mentzelia sect. Bicuspidaria]]
|-id=key-0-2
|2
|Stamen filaments filiform or outer dorsiventrally flattened, inner filiform, 0 or 5+ outermost petaloid, if 5+, seeds winged.
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Ovules and seeds oriented perpendicular to long axis of ovary; seeds winged; 5 outermost stamen filaments usually petaloid, sometimes not.
|[[Mentzelia sect. Bartonia|Mentzelia sect. Bartonia]]
|-id=key-0-3
|3
|Ovules and seeds oriented parallel to long axis of ovary; seeds not winged (occasionally winged in Mentzelia lindleyi); 5 outermost stamen filaments not petaloid.
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Plants perennial.
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Leaf blades, at least some, with broad basal lobes, margins flat; capsules usually subcylindric, clavate, lingulate, or funnelform, sometimes ovoid; seeds oblong, ovoid, or pyriform, coat cells oblong.
|[[Mentzelia sect. Mentzelia|Mentzelia sect. Mentzelia]]
|-id=key-0-5
|5
|Leaf blades without broad basal lobes, margins revolute; capsules ovoid to urceolate; seeds ovoid to bottle-shaped, coat cells polygonal.
|[[Mentzelia sect. Micromentzelia|Mentzelia sect. Micromentzelia]]
|-id=key-0-4
|4
|Plants annual.
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Leaf blades, at least some, with broad basal lobes; seeds oblong, ovoid, or pyriform, dorsiventrally flattened to trigonal, coat cells oblong, much longer than wide, anticlinal walls sinuous; basal rosette of leaves absent, proximalmost internodes 10+ mm.
|[[Mentzelia sect. Mentzelia|Mentzelia sect. Mentzelia]]
|-id=key-0-6
|6
|Leaf blades without broad basal lobes; seeds triangular prisms or irregularly polygonal, coat cells polygonal, ± isodiametric, anticlinal walls straight; basal rosette of leaves present, persistent or not, proximalmost internodes to 5 mm.
|[[Mentzelia sect. Trachyphytum|Mentzelia sect. Trachyphytum]]
|}
</div></div><!--

-->{{#Taxon:
name=Mentzelia
|author=Larry Hufford;John J. Schenk;Joshua M. Brokaw
|authority=Linnaeus
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Loasaceae
|distribution=w;c;se North America;Mexico;West Indies;Central America;South America
|reference=None
|publication title=Sp. Pl.
|publication year=1753
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V12/V12_19.xml
|genus=Mentzelia
|all architecture=heteromorphic;monomorphic
|all arrangement or course or shape=linear;linear
|all position=outer
|all shape=oblanceolate;spatulate;oblanceolate;spatulate;elliptic;flattened;flattened;filiform
|blade shape=unlobed;lobed;orbiculate;obovate;unlobed;lobed;orbiculate;obovate;unlobed;lobed;orbiculate;obovate;oblanceolate;spatulate;linear;lanceolate;elliptic;ovate;cordate;deltate;hastate
|fruits capsule course=curved;straight
|fruits capsule dehiscence=dehiscing
|fruits capsule shape=s--shaped;clavate;urceolate;ovoid;cylindric;subcylindric;lingulate;cup-shaped
|hypanthium fusion=free;adnate
|inflorescences dichasium architecture or arrangement or growth form=solitary
|inflorescences flower architecture or arrangement or growth form=solitary
|inner stamen arrangement or course or shape=linear
|inner stamen length or size=longer
|inner stamen shape=flattened;filiform
|leaf position=cauline;cauline;basal
|margin architecture or shape=dentate
|margin shape=entire;crenate;entire;crenate;serrate
|nectary position or shape=distal
|pedicel length=not elongating
|peduncle prominence=inconspicuous
|perianth whorl variability=differentiated
|petal coloration=red;orange;yellow;orange;yellow;white
|petal fusion=connate;distinct
|petal orientation=spreading;erect
|petal pubescence=hairy;glabrous
|petal shape=obovate;oblanceolate;obovate;oblanceolate;elliptic;ovate;spatulate
|petiole presence=absent;absent
|pistil architecture=3-carpellate
|placenta arrangement=parietal
|seed architecture=not winged;winged
|seed atypical quantity=1;2
|seed quantity=2;60
|seed shape=not;flattened;polygonal;pyriform;bottle--shaped;oblong;ovoid
|seed some measurement=0.5mm;4.5mm
|sepal coloration=green
|sepal duration=persistent
|sepal fusion=connate
|sepal height or length or size=shorter
|sepal shape=lanceolate;narrowly ovate
|stamen position=included;exserted
|stamen quantity=8;45
|staminode presence=absent;absent
|stem orientation=decumbent;clambering;decumbent;clambering;erect
|stigma relief=papillate
|stigma shape=3-lobed;lingulate
|surface architecture or pubescence or relief=smooth
|trichome architecture or shape=barbed;barbed
|trichome atypical quantity=2;1
|trichome shape=pointed
|whole_organism duration=perennial;biennial;perennial;biennial;annual;perennial;biennial;perennial;biennial;annual
|whole_organism growth form=subshrub;herb
|x chromosome quantity=9
}}<!--

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