Rumex spinosus

{{Short description|Species of flowering plant}} {{Speciesbox |image = Emexspinosa.jpg |taxon = Rumex spinosus |authority = L.<ref name=POWO_697516-1/> |synonyms_ref = <ref name=POWO_697516-1/> |synonyms = {{Species list |Centopodium spinosum|(L.) Burch. |Emex spinosa|(L.) Campd. |Rumex glaber|Forssk. |Vibo spinosa|(L.) Medik. }} }}

'''''Rumex spinosus''''' (synonym '''''Emex spinosa'''''), commonly known as '''devil's thorn''', '''spiny dock''', or '''lesser jack''', is an annual herbaceous plant of the Polygonaceae. It originates in the warmer parts of the Old World, but now has spread with humans to other places. It is common in disturbed areas, especially in sandy soils. It has shown some weedy behaviour in restricted areas within southern Australia.<ref>{{cite web |author=Yeoh P, Scott JK |title=Emex (Emex australis) |work=CSIRO Entomology |publisher=CSIRO |url=http://www.ento.csiro.au/weeds/emex/index.html |access-date=2007-08-14 |url-status=dead |archiveurl=https://web.archive.org/web/20070903083658/http://www.ento.csiro.au/weeds/emex/index.html |archivedate=2007-09-03 }}</ref>

==Description== The lesser jack tends to grow as a sprawling weed. The leaves are plain in shape, resembling spinach. The flowers of different sexes are clustered separately on the same plant. The plant produces many seeds with a hard, prickly casing. These are produced both in clusters along the branches and at the base of the stem. The root is thick and succulent. At the end of the plant's life, the root dries up and pulls the seeds at the base of the stem into the ground. The spiny, durable seeds make the plant a nuisance around human habitats, much like the similarly shaped seeds of ''Tribulus terrestris''.

==Taxonomy== ''Rumex spinosus'' was first described by Carl Linnaeus in 1753. It was transferred to the genus ''Emex'' by Francisco Campderá in 1819.<ref name=IPNI_697516-1>{{cite web |title=Plant Name Details for ''Rumex spinosus'' L. |work=The International Plant Names Index |url=http://www.ipni.org/ipni/idPlantNameSearch.do?id=697516-1 |access-date=2019-02-26 }}</ref> However in 2015, Schuster et al. demoted ''Emex'' to a subgenus of ''Rumex'', restoring the species to Linnaeus's original genus.<ref name=SchuReveBaylKron15>{{Citation |mode=cs1|last1=Schuster |first1=Tanja M. |last2=Reveal |first2=James L. |last3=Bayly |first3=Michael J. |last4=Kron |first4=Kathleen A. |date=2015 |title=An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of ''Oxygonum'', ''Pteroxygonum'', and ''Rumex'', and a new circumscription of ''Koenigia'' |journal=Taxon |volume=64 |issue=6 |pages=1188–1208 |doi=10.12705/646.5 |name-list-style=amp }}</ref> a move accepted by Plants of the World Online, among other sources.<ref name=POWO_697516-1/>

==Uses== Although bitter, the root and leaves can be eaten.

==References== {{Reflist|refs= <ref name=POWO_697516-1>{{cite web |title=''Rumex spinosus'' <small>L.</small> |work=Plants of the World Online |publisher=Royal Botanic Gardens, Kew|url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:697516-1 |access-date=2019-02-26 }}</ref> }}

spinosus Category:Plants described in 1753 Category:Botanical taxa named by Carl Linnaeus {{Polygonaceae-stub}}