View source for Oenothera sect. Gaura

{{Treatment/ID
|accepted_name=Oenothera sect. Gaura
|accepted_authority=(Linnaeus) W. L. Wagner & Hoch
|publications={{Treatment/Publication
|title=Syst. Bot. Monogr.
|place=83: 165. 2007
|year=2007
}}
|basionyms={{Treatment/ID/Basionym
|name=Gaura
|authority=Linnaeus
|rank=genus
|publication_title=Sp. Pl.
|publication_place=1: 347.  1753
}}
|synonyms=
|hierarchy=Onagraceae;Onagraceae subfam. Onagroideae;Onagraceae tribe Onagreae;Oenothera;Oenothera sect. Gaura
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Onagraceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Onagraceae subfam. Onagroideae]]</div><div class="higher-taxon"><small>tribe</small>[[Onagraceae tribe Onagreae]]</div><div class="higher-taxon"><small>genus</small>[[Oenothera]]</div><div class="higher-taxon"><small>section</small>[[Oenothera sect. Gaura]]</div></div>
|volume=Volume 10
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-d0_s0" data-properties=""><b>Herbs </b>annual, biennial, or perennial, caulescent;</span> <span class="statement" id="st-d0_s1" data-properties="herb duration;herb duration;herb duration;herb duration;herb duration;herb architecture;herb texture;herb texture">from a taproot, sometimes woody or producing rhizomes.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem orientation;stem growth form or orientation;stem architecture;stem architecture"><b>Stems </b>usually erect or ascending, sometimes decumbent, branched or unbranched.</span> <span class="statement" id="st-d0_s3" data-properties="leaf position;leaf atypical some measurement;leaf atypical some measurement;leaf some measurement"><b>Leaves </b>in a basal rosette and cauline (sometimes not present at flowering), (0.5–) 2–8 (–13) cm;</span> <span class="statement" id="st-d0_s4" data-properties="blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape;blade margin shape">blade margins sinuate-dentate to denticulate, serrate, lobed, or entire.</span> <span class="statement" id="st-d0_s5" data-properties="flower architecture or arrangement or growth form;flower orientation;flower orientation"><b>Inflorescences </b>solitary flowers in axils of distal leaves, forming a spike, erect or nodding.</span> <span class="statement" id="st-d0_s6" data-properties=""><b>Flowers </b>opening near sunset or sunrise;</span> <span class="statement" id="st-d0_s7" data-properties="bud orientation;bud shape;tip fusion">buds erect, terete, without free tips;</span> <span class="statement" id="st-d0_s8" data-properties="floral-tube atypical some measurement;floral-tube some measurement;floral-tube pubescence;within position or shape;within quantity">floral-tube 1.5–20 [–42] mm, usually lanate in distal 1/2 within;</span> <span class="statement" id="st-d0_s9" data-properties="sepal architecture or dehiscence;sepal fusion;sepal orientation;sepal arrangement">sepals splitting along one suture, remaining coherent and reflexed as a unit at anthesis, or separating in pairs or sometimes individually;</span> <span class="statement" id="st-d0_s10" data-properties="petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal coloration;petal shape;petal shape;petal shape;petal shape;petal shape;petal shape">petals white [rarely yellow], fading pink to red, purple, or off-white, spatulate to elliptic, rhombic, or, sometimes, oblanceolate, usually clawed;</span> <span class="statement" id="st-d0_s11" data-properties="basal scale some measurement;mouth condition;mouth size;mouth presence">filaments with basal scale 0.3–0.5 mm, these nearly closing mouth of floral-tube, or sometimes reduced or absent;</span> <span class="statement" id="st-d0_s12" data-properties="stigma shape;lobe quantity;lobe arrangement or course or shape">stigma deeply divided into (3 or) 4 linear lobes.</span> <span class="statement" id="st-d0_s13" data-properties="capsule texture;capsule shape;capsule shape;capsule shape;capsule shape;capsule shape;capsule shape;capsule shape;capsule shape;capsule shape;capsule shape;capsule architecture;apex shape;apex shape;apex shape;apex shape;apex shape;apex dehiscence"><b>Capsules </b>woody and nutlike, ovoid, fusiform, lanceoloid, ellipsoid, obovoid, or pyramidal, (3-angled or) 4-angled, sometimes weakly so, or (3-winged or) 4-winged, apex acute to attenuate or, sometimes, rounded, indehiscent, septa fragile, not evident at maturity;</span> <span class="statement" id="st-d0_s14" data-properties="septum fragility;septum prominence;septum architecture;septum architecture">sessile, sometimes disarticulating from plant at maturity.</span> <span class="statement" id="st-d0_s15" data-properties="surface atypical quantity;surface quantity;surface shape;surface shape;surface architecture or pubescence or relief"><b>Seeds </b>reduced to 1–4 (–8), usually ovoid, rarely oblanceoloid (O. glaucifolia), surface smooth.</span> <span class="statement" id="st-d0_s16" data-properties="seed size;2n chromosome quantity;2n chromosome quantity;2n chromosome quantity;2n chromosome quantity">2n = 14, 28, 42, 56.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico;Central America (Guatemala);in South America;Europe;Asia;s Africa;Australia
|discussion=<p>Species 25 (23 in the flora).</p><!--
--><p>Section Gaura consists of 25 species (26 taxa) that are subdivided into eight subsections [seven in the flora area; subsect. Gauridium (Spach) W. L. Wagner & Hoch is is found only in Mexico]. All species have indehiscent capsules, a feature otherwise found in Oenothera only in O. canescens (sect. Gauropsis). Oenothera havardii (sect. Paradoxus) and O. linifolia (sect. Peniophyllum) have tardily and only partially dehiscent capsules. Twenty-one species in four subsections (Campogaura, Gaura, Stipogaura, and Xenogaura) have zygomorphic flowers; the other four subsections (Gauridium, Schizocarya, Stenosiphon, and Xerogaura), each with a single species, have actinomorphic, or nearly actinomorphic, flowers. Since Linnaeus described Gaura, it has been maintained as distinct at the generic level and, at various times, even at the tribal level. Its distinct status rested on several characteristic features including a scale at the base of the filaments; a peltate indusium at the base of the stigma; indehiscent, nutlike capsules; and seeds reduced to 1–4(–8) (P. H. Raven and D. P. Gregory 1972[1973]; W. L. Wagner et al. 2007). The most recent molecular studies (G. D. Hoggard et al. 2004; R. A. Levin et al. 2004) place Gaura strongly within the Oenothera clade and equally strongly in a clade with other sections possessing winged/angled capsules that are sometimes indehiscent or nearly so. Hoggard et al. found strong support for the inclusion of the monotypic Stenosiphon within Gaura; Levin et al. concurred, finding strong support for the monophyly of the Gaura lineage, but placed it unequivocally within Oenothera. Reconsidering the distinctive features of Gaura, Wagner et al. found that the indusium characterizes the whole genus Oenothera, and the indehiscent fruits seem to characterize a larger clade in the genus. The reduction in seed number appears to be a strong synapomorphy for the reconstituted Oenothera sect. Gaura. Wagner et al. recognized eight subsections within sect. Gaura that also includes Stenosiphon. The subsections are arranged according to the synthesis of morphological characters, crossing analyses, and molecular data (Raven and Gregory; Wagner et al.). Oenothera anomala Curtis and O. hexandra (Ortega) W. L. Wagner & Hoch are Mexican species that occur well south of the flora area.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Filaments without basal scales or with minute scale; flowers nearly actinomorphic.
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Floral tubes 6–17 mm; herbs probably biennial, glaucous at least in proximal part 17k.
|[[Oenothera subsect. Stenosiphon|Oenothera subsect. Stenosiphon]]
|-id=key-0-2
|2
|Floral tubes 1.5–5 mm; herbs annual, not glaucous 17k.
|[[Oenothera subsect. Schizocarya|Oenothera subsect. Schizocarya]]
|-id=key-0-1
|1
|Filaments with basal scales; flowers zygomorphic or sometimes nearly actinomorphic.
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Capsules with a slender stipe (0.5–)2–10 mm 17k.
|[[Oenothera subsect. Stipogaura|Oenothera subsect. Stipogaura]]
|-id=key-0-3
|3
|Capsules usually with a stipe 0.2–2.2 mm.
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Capsules pyramidal in distal 1/2, abruptly constricted to a cylindrical proximal part.
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Capsules not conspicuously bulging at base of distal pyramidal 1/2; plants not rhizomatous 17k.
|[[Oenothera subsect. Campogaura|Oenothera subsect. Campogaura]]
|-id=key-0-5
|5
|Capsule conspicuously bulging at base of the distal pyramidal 1/2; plants rhizomatous 17k.
|[[Oenothera subsect. Xenogaura|Oenothera subsect. Xenogaura]]
|-id=key-0-4
|4
|Capsules fusiform, ellipsoid, ovoid, or obovoid and then abruptly constricted or cuneate to base.
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Capsules ellipsoid, ovoid, or obovoid 17k.
|[[Oenothera subsect. Gaura|Oenothera subsect. Gaura]]
|-id=key-0-6
|6
|Capsules fusiform.
|[[#key-0-7| > 7]]
|-id=key-0-7
|7
|Floral tubes 9–13 mm; flowers nearly actinomorphic 17k.
|[[Oenothera subsect. Xerogaura|Oenothera subsect. Xerogaura]]
|-id=key-0-7
|7
|Floral tubes 3–11(–13) mm; flowers zygomorphic 17k.
|[[Oenothera subsect. Campogaura|Oenothera subsect. Campogaura]]
|}
</div></div><!--

-->{{#Taxon:
name=Oenothera sect. Gaura
|authority=(Linnaeus) W. L. Wagner & Hoch
|rank=section
|parent rank=genus
|synonyms=
|basionyms=Gaura
|family=Onagraceae
|distribution=North America;Mexico;Central America (Guatemala);in South America;Europe;Asia;s Africa;Australia
|reference=None
|publication title=Syst. Bot. Monogr.
|publication year=2007
|special status=
|source xml=
|subfamily=Onagraceae subfam. Onagroideae
|tribe=Onagraceae tribe Onagreae
|genus=Oenothera
|section=Oenothera sect. Gaura
|2n chromosome quantity=56;42;28;14
|apex dehiscence=indehiscent
|apex shape=rounded;,;acute;attenuate
|basal scale some measurement=0.3mm;0.5mm
|blade margin shape=sinuate-dentate;denticulate serrate lobed or entire
|bud orientation=erect
|bud shape=terete
|capsule architecture=4-winged
|capsule shape=4-angled;pyramidal;obovoid;pyramidal;obovoid;ellipsoid;lanceoloid;fusiform;ovoid;nutlike
|capsule texture=woody
|floral-tube atypical some measurement=20mm;42mm
|floral-tube pubescence=lanate
|floral-tube some measurement=1.5mm;20mm
|flower architecture or arrangement or growth form=solitary
|flower orientation=nodding;erect
|herb architecture=caulescent
|herb duration=perennial;biennial;perennial;biennial;annual
|herb texture=producing rhizomes;woody
|leaf atypical some measurement=8cm;13cm
|leaf position=cauline
|leaf some measurement=2cm;8cm
|lobe arrangement or course or shape=linear
|lobe quantity=4
|mouth condition=closing
|mouth presence=absent
|mouth size=reduced
|petal coloration=fading pink;red purple or off-white
|petal shape=clawed;oblanceolate;rhombic;spatulate;elliptic
|seed size=reduced
|sepal architecture or dehiscence=splitting
|sepal arrangement=separating
|sepal fusion=coherent
|sepal orientation=reflexed
|septum architecture=disarticulating;sessile
|septum fragility=fragile
|septum prominence=not evident
|stem architecture=unbranched;branched
|stem growth form or orientation=decumbent
|stem orientation=ascending;erect
|stigma shape=divided
|surface architecture or pubescence or relief=smooth
|surface atypical quantity=4;8
|surface quantity=1;4
|surface shape=oblanceoloid;ovoid
|tip fusion=free
|within position or shape=distal
|within quantity=1/2
}}<!--

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