View source for Emex

{{Treatment/ID
|accepted_name=Emex
|accepted_authority=Necker ex Campderá
|publications={{Treatment/Publication
|title=Monogr. Rumex,
|place=56, plate 1, fig. 1. 1819
|year=1819
}}
|basionyms=
|synonyms=
|hierarchy=Polygonaceae;Polygonaceae subfam. Polygonoideae;Emex
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Polygonaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Polygonaceae subfam. Polygonoideae]]</div><div class="higher-taxon"><small>genus</small>[[Emex]]</div></div>
|etymology=Latin, ex, and Rumex, alluding to segregation from that genus
|volume=Volume 5
|mention_page=page 216, 218, 480, 486
|treatment_page=page 487
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Herbs,</b> annual; taprooted. <b>Stems</b> prostrate to erect, glabrous. <b>Leaves</b> deciduous, cauline, alternate, petiolate; ocrea often deciduous, chartaceous; blade subhastate, triangular, or ovate to ovate-oblong, margins entire to obscurely crenulate or dentate, sometimes undulate. <b>Inflorescences</b> terminal and axillary, racemelike, pedunculate. <b>Pedicels</b> present on staminate flowers, absent or nearly so on pistillate flowers. <b>Flowers</b> unisexual, all plants having both staminate and pistillate flowers, the two types segregated in different inflorescences, base not stipelike; perianth accrescent (pistillate) or nonaccrescent (staminate), greenish, campanulate, glabrous; tepals (5–)6, sepaloid, dimorphic, especially in pistillate flowers. <b>Staminate</b> flowers 1–8 per ocreate fascicle, terminal and axillary; tepals distinct, subequal; stamens 4–6; filaments distinct, free, glabrous; anthers yellowish to reddish, elliptic to ovate. <b>Pistillate</b> flowers 1–7 per ocreate fascicle, axillary; tepals connate basally, outer 3 each with apex ending in a stout spine in fruit, inner 3 erect, tuberculate; styles 3, erect, distinct; stigmas penicillate. <b>Achenes</b> included in indurate perianth, brown, not winged, 3-gonous, glabrous. <b>Seeds</b>: embryo curved. <b>x</b> = 10.</span><!--

-->{{Treatment/Body
|distribution=tropical to subtropical or temperate regions;South America;Eurasia;Africa;Atlantic Islands;Pacific Islands.
|introduced=true
|discussion=<p>Species 2 (2 in the flora).</p><!--
--><p>Both species of <i>Emex</i> are on the United States federal noxious weed list. <i>Emex australis</i> appears to be a more serious threat to agriculture and livestock production than does <i>E. spinosa</i>, based on experience in other parts of the world. The former is a serious agricultural pest in southern Australia, where it was introduced in the 1830s. <i>Emex spinosa</i> also was introduced there, apparently in the mid-1900s. The two species were formerly geographically isolated, but hybrids between them have recently been reported in Australia (E. Putievsky et al. 1980). Hybrids exhibit irregular meiosis and high sterility when self-pollinated; backcrosses with either parent often yield viable seeds.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Fruiting perianths 7-9 × 9-10 mm, spines 5-10 mm; inner tepals of pistillate flowers broadly triangular-ovate, apex mucronate
|[[Emex australis|Emex australis]]
|-id=key-0-1
|1
|Fruiting perianths 5-6 × 5-6 mm, spines 2-4 mm; inner tepals of pistillate flowers linear-lanceolate, apex acute
|[[Emex spinosa|Emex spinosa]]
|}
</div></div><!--

-->{{#Taxon:
name=Emex
|author=Craig C. Freeman
|authority=Necker ex Campderá
|rank=genus
|parent rank=subfamily
|synonyms=
|basionyms=
|family=Polygonaceae
|illustrator=Bee F. Gunn
|illustration copyright=Flora of North America Association
|distribution=tropical to subtropical or temperate regions;South America;Eurasia;Africa;Atlantic Islands;Pacific Islands.
|introduced=true
|reference=None
|publication title=Monogr. Rumex,
|publication year=1819
|special status=
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V5/V5_1015.xml
|subfamily=Polygonaceae subfam. Polygonoideae
|genus=Emex
}}<!--

-->[[Category:Treatment]][[Category:Polygonaceae subfam. Polygonoideae]]