View source for Tetraneuris

{{Treatment/ID
|accepted_name=Tetraneuris
|accepted_authority=Greene
|publications={{Treatment/Publication
|title=Pittonia
|place=3: 265. 1898
|year=1898
}}
|common_names=Bitterweed
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Heliantheae;Asteraceae (tribe Heliantheae) subtribe Gaillardiinae;Tetraneuris
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Heliantheae]]</div><div class="higher-taxon"><small>subtribe</small>[[Asteraceae (tribe Heliantheae) subtribe Gaillardiinae]]</div><div class="higher-taxon"><small>genus</small>[[Tetraneuris]]</div></div>
|etymology=Greek tetra, four, and neuron, nerve, alluding to venation of ray floret corollas
|volume=Volume 21
|mention_page=page 415, 416, 437
|treatment_page=page 447
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole-organism some measurement;whole-organism duration;whole-organism some measurement;whole-organism duration"><b>Annuals </b>or perennials, 2–50+ cm (perennials with ± branched, woody caudices).</span> <span class="statement" id="st-d0_s1" data-properties="stem quantity;stem orientation;stem orientation;stem architecture;stem architecture"><b>Stems </b>1–60, erect or ± decumbent, unbranched or sparingly branched distally.</span> <span class="statement" id="st-d0_s2" data-properties=""><b>Leaves </b>all basal, or basal-proximal, or basal and cauline;</span> <span class="statement" id="st-d0_s3" data-properties="">alternate;</span> <span class="statement" id="st-d0_s4" data-properties="leaf position;leaf position;leaf arrangement;leaf architecture;leaf architecture">petiolate or sessile;</span> <span class="statement" id="st-d0_s5" data-properties="blade shape;blade shape;ultimate margin architecture or shape;ultimate margin shape;face pubescence;face pubescence;face architecture;face architecture">blades (usually with distinct midribs) mostly oblanceolate to linear or filiform, sometimes lobed, ultimate margins usually entire, sometimes toothed, faces glabrous or ± hairy, eglandular or ± glanddotted.</span> <span class="statement" id="st-d0_s6" data-properties="head architecture;head architecture;head arrangement;head arrangement;array architecture;array arrangement"><b>Heads </b>radiate or discoid, borne singly or in paniculiform to corymbiform or fastigiate arrays.</span> <span class="statement" id="st-d0_s7" data-properties="involucre shape;involucre diameter"><b>Involucres </b>hemispheric to campanulate 6–20 mm diam.</span> <span class="statement" id="st-d0_s8" data-properties="phyllary quantity;series quantity"><b>Phyllaries </b>11–60+ in 3 series (mostly spreading to erect in fruit, distinct, herbaceous; outer with or without scarious margins, abaxial faces ± hairy; mid usually same number as, alternating with, and similar to outer, almost always with ± scarious margins; inner narrower than others, margins scarious).</span> <span class="statement" id="st-d0_s9" data-properties="receptacle shape;receptacle relief;receptacle architecture or pubescence or relief;receptacle architecture"><b>Receptacles </b>hemispheric to conic, shallowly pitted or smooth, epaleate.</span> <span class="statement" id="st-d0_s10" data-properties="ray-floret presence;ray-floret quantity;ray-floret architecture;ray-floret reproduction"><b>Ray-</b>florets 0 or 7–27, pistillate, fertile;</span> <span class="statement" id="st-d0_s11" data-properties="corolla coloration">corollas (usually marcescent) yellow (laminae fan-shaped to oblanceolate, usually 3-lobed).</span> <span class="statement" id="st-d0_s12" data-properties="disc-floret quantity;disc-floret reproduction;disc-floret reproduction"><b>Disc-</b>florets 20–250+, bisexual, fertile;</span> <span class="statement" id="st-d0_s13" data-properties="corolla coloration;corolla coloration;corolla coloration;tube height or length or size;lobe quantity;lobe shape">corollas yellow proximally, yellow or purplish distally, tubes shorter than cylindric to cylindro-campanulate throats, lobes 5, ± deltate.</span> <span class="statement" id="st-d0_s14" data-properties="cypsela shape;cypsela pubescence"><b>Cypselae </b>± obpyramidal, moderately to densely hairy;</span> <span class="statement" id="st-d0_s15" data-properties="pappus duration">pappi persistent, of 4–8 usually aristate, scales.</span> <span class="statement" id="st-d0_s16" data-properties="x chromosome quantity">x = 15.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico
|discussion=<p>Species 9 (9 in the flora).</p><!--
--><p>Here, strigoso-canescent refers to often silvery induments (hairs tightly appressed, relatively short, 1–1.5 mm) of Tetraneuris argentea and T. acaulis var. acaulis. Such induments contrast with lanuginose or sericeous induments (hairs spreading, ca 1.5–3 mm) in other taxa, including T. ivesiana and the other three varieties of T. acaulis.</p>
|tables=
|references={{Treatment/Reference
|id=bierner1998a
|text=Bierner, M. W. and R. K. Jansen. 1998. Systematic implications of DNA restriction site variation in Hymenoxys and Tetraneuris (Asteraceae, Helenieae, Gaillardiinae). Lundellia 1: 17–26.
}}{{Treatment/Reference
|id=bierner2003a
|text=Bierner, M. W. and B. L. Turner. 2003. Taxonomy of Tetraneuris (Asteraceae: Helenieae: Tetraneurinae). Lundellia 6: 44–96.
}}{{Treatment/Reference
|id=greene1898a
|text=Greene, E. L. 1898. Studies in the Compositae—VII. 1. Some helenioid genera. Tetraneuris. Pittonia 3: 264–270.
}}{{Treatment/Reference
|id=rydberg1915a
|text=Rydberg, P. A. 1915b. Tetraneuris. In: N. L. Britton et al., eds. 1905+. North American Flora.... 47+ vols. New York. Vol. 34, 100–108.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Annuals
|[[Tetraneuris linearifolia|Tetraneuris linearifolia]]
|-id=key-0-1
|1
|Perennials (with caudices)
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Caudices: branches not notably thickened distally; leaves all basal-proximal (not tightly clustered, internodes often evident)
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Caudices: branches notably thickened distally; leaves all basal or basal and cauline (basal leaves tightly clustered, internodes usually not evident)
|[[#key-0-4| > 4]]
|-id=key-0-3
|3
|Stems erect; leaves sparsely to densely hairy, not woolly; Colorado, Kansas,Nebraska, New Mexico, Oklahoma, Texas
|[[Tetraneuris scaposa|Tetraneuris scaposa]]
|-id=key-0-3
|3
|Stems erect or ± decumbent; leaves moderately to densely woolly; s Texas
|[[Tetraneuris turneri|Tetraneuris turneri]]
|-id=key-0-4
|4
|Leaves basal and cauline
|[[#key-0-5| > 5]]
|-id=key-0-4
|4
|Leaves all basal
|[[#key-0-6| > 6]]
|-id=key-0-5
|5
|Leaf blades ± densely strigoso-canescent
|[[Tetraneuris argentea|Tetraneuris argentea]]
|-id=key-0-5
|5
|Leaf blades glabrous or sparsely to moderately lanuginose to sericeous
|[[Tetraneuris ivesiana|Tetraneuris ivesiana]]
|-id=key-0-6
|6
|Ray florets 0 (leaves densely hairy, not strigoso-canescent; Yavapai County,Arizona)
|[[Tetraneuris verdiensis|Tetraneuris verdiensis]]
|-id=key-0-6
|6
|Ray florets usually 7–27 (if 0, leaves strigoso-canescent; widespread)
|[[#key-0-7| > 7]]
|-id=key-0-7
|7
|Rays 14–27; pappus scales usually non-aristate; Ontario, Illinois, Ohio
|[[Tetraneuris herbacea|Tetraneuris herbacea]]
|-id=key-0-7
|7
|Rays 7–15(–21); pappus scales aristate; North Dakota to Texas and west
|[[#key-0-8| > 8]]
|-id=key-0-8
|8
|Leaves (midribs usually distinct) glabrous or usually sparsely, sometimes moderately or densely hairy (not strigoso-canescent or sericeous), gland-dotted; outer phyllaries 4–8, margins (0.3–)0.5–1.2 mm wide, usuallyconspicuously scarious
|[[Tetraneuris torreyana|Tetraneuris torreyana]]
|-id=key-0-8
|8
|Leaves (midribs not very distinct) glabrous or ± hairy, often lanuginose, sericeous, or strigoso-canescent, eglandular or ± gland-dotted; outer phyllaries 6–12, margins 0–0.4 mm wide, sometimes slightly scarious
|[[Tetraneuris acaulis|Tetraneuris acaulis]]
|}
</div></div><!--

-->{{#Taxon:
name=Tetraneuris
|author=Mark W. Bierner;Billie L. Turner
|authority=Greene
|rank=genus
|parent rank=subtribe
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=North America;Mexico
|reference=bierner1998a;bierner2003a;greene1898a;rydberg1915a
|publication title=Pittonia
|publication year=1898
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V19-20-21/V21_1120.xml
|tribe=Asteraceae tribe Heliantheae
|subtribe=Asteraceae (tribe Heliantheae) subtribe Gaillardiinae
|genus=Tetraneuris
|array architecture=paniculiform;corymbiform
|array arrangement=fastigiate
|blade shape=lobed;mostly oblanceolate;linear or filiform
|corolla coloration=purplish;yellow;yellow;yellow
|cypsela pubescence=hairy
|cypsela shape=obpyramidal
|disc-floret quantity=20;250
|disc-floret reproduction=fertile;bisexual
|face architecture=more or less;eglandular
|face pubescence=hairy;glabrous
|head architecture=discoid;radiate
|head arrangement=in paniculiform to corymbiform or fastigiate arrays;singly
|involucre diameter=6mm;20mm
|involucre shape=hemispheric;campanulate
|leaf architecture=sessile;petiolate
|leaf arrangement=alternate
|leaf position=basal-proximal;basal-proximal
|lobe quantity=5
|lobe shape=deltate
|pappus duration=persistent
|phyllary quantity=11;60
|ray-floret architecture=pistillate
|ray-floret presence=absent
|ray-floret quantity=7;27
|ray-floret reproduction=fertile
|receptacle architecture=epaleate
|receptacle architecture or pubescence or relief=smooth
|receptacle relief=pitted
|receptacle shape=hemispheric;conic
|series quantity=3
|stem architecture=branched;unbranched
|stem orientation=decumbent;erect
|stem quantity=1;60
|tube height or length or size=shorter
|ultimate margin architecture or shape=entire
|ultimate margin shape=toothed
|whole-organism duration=perennial;annual
|whole-organism some measurement=2cm;50cm
|x chromosome quantity=15
}}<!--

-->[[Category:Treatment]][[Category:Asteraceae (tribe Heliantheae) subtribe Gaillardiinae]]