Rumex hypogaeus (synonymEmex australis), commonly known in English as southern threecornerjack,[2]devil's thorn,[citation needed] or double gee[3] (also doublegee, from the old Afrikaner name dubbeltge-doorn - 'double thorned'), is a herbaceous plant of the Polygonaceae. It is native in South Africa and is an invasive species in Australia, Texas in the USA & Pakistan.
It grows to heights of from 10 to 60 cm and its stems may be prostrate, decumbent, or ascending. The base is often reddish. The leaves are stalked and without any surface covering, with the leaf blade being 1-10 by 0.5–6 cm. There are 1 to 8 flowers with stamens per sheathed bundle and these flowers have narrow oblong tepals which are 1.5–2 mm. The female flowers occur as groups of 1 to 4 per sheathed bundle, and the outer tepals are ovate to oblong and 4–6 mm in fruit, while the inner tepals are broadly triangular and, 5–6 mm in fruit. The achenes (dry 1-seeded fruits not opening at maturity) are 4-6 by 2–3 mm, and shiny.[4]
It favours disturbed sites, on sandy soils. It is native to South Africa[1] and has become naturalised in California, Trinidad, Europe, India, Pakistan, Taiwan, Hawaii, and Australia.[4]
Weededit
Common names in Australia, where it is a weed, include: spiny emex, doublegee, double gee, double-gee, three corner jack, three-cornered jack, goat's head burr, goathead, jackie, prickly jack, cape spinach, devil's face, devil's thorn, bullhead, bull head, and cat's head.[5]
Treatmentedit
Small infestations and isolated plants of Rumex hypogaeus can be dug out. When plants are seeding then they should be destroyed by burning. Control programs work best when all plants are killed shortly after having emergence, and should continue for several years.[6][5]
Galleryedit
The fruits, most often almost black in colour
Referencesedit
^ ab"Rumex hypogaeus T.M.Schust. & Reveal | Plants of the World Online | Kew Science". Plants of the World Online. Retrieved 2020-07-06.
^USDA, NRCS (n.d.). "Emex australis". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 18 January 2016.
rumex, hypogaeus, synonym, emex, australis, commonly, known, english, southern, threecornerjack, devil, thorn, citation, needed, double, also, doublegee, from, afrikaner, name, dubbeltge, doorn, double, thorned, herbaceous, plant, polygonaceae, native, south, . Rumex hypogaeus synonym Emex australis commonly known in English as southern threecornerjack 2 devil s thorn citation needed or double gee 3 also doublegee from the old Afrikaner name dubbeltge doorn double thorned is a herbaceous plant of the Polygonaceae It is native in South Africa and is an invasive species in Australia Texas in the USA amp Pakistan Rumex hypogaeusScientific classificationKingdom PlantaeClade TracheophytesClade AngiospermsClade EudicotsOrder CaryophyllalesFamily PolygonaceaeGenus RumexSpecies R hypogaeusBinomial nameRumex hypogaeusT M Schust amp RevealSynonyms 1 Emex australis Steinh Vibo australis Steinh Greene Contents 1 Description 2 Distribution and habitat 3 Weed 3 1 Treatment 4 Gallery 5 References 6 External linksDescription editIt grows to heights of from 10 to 60 cm and its stems may be prostrate decumbent or ascending The base is often reddish The leaves are stalked and without any surface covering with the leaf blade being 1 10 by 0 5 6 cm There are 1 to 8 flowers with stamens per sheathed bundle and these flowers have narrow oblong tepals which are 1 5 2 mm The female flowers occur as groups of 1 to 4 per sheathed bundle and the outer tepals are ovate to oblong and 4 6 mm in fruit while the inner tepals are broadly triangular and 5 6 mm in fruit The achenes dry 1 seeded fruits not opening at maturity are 4 6 by 2 3 mm and shiny 4 It flowers all year round 4 Distribution and habitat editIt favours disturbed sites on sandy soils It is native to South Africa 1 and has become naturalised in California Trinidad Europe India Pakistan Taiwan Hawaii and Australia 4 Weed editCommon names in Australia where it is a weed include spiny emex doublegee double gee double gee three corner jack three cornered jack goat s head burr goathead jackie prickly jack cape spinach devil s face devil s thorn bullhead bull head and cat s head 5 Treatment edit Small infestations and isolated plants of Rumex hypogaeus can be dug out When plants are seeding then they should be destroyed by burning Control programs work best when all plants are killed shortly after having emergence and should continue for several years 6 5 Gallery edit nbsp The fruits most often almost black in colour nbsp References edit a b Rumex hypogaeus T M Schust amp Reveal Plants of the World Online Kew Science Plants of the World Online Retrieved 2020 07 06 USDA NRCS n d Emex australis The PLANTS Database plants usda gov Greensboro North Carolina National Plant Data Team Retrieved 18 January 2016 BSBI List 2007 xls Botanical Society of Britain and Ireland Archived from the original xls on 2015 06 26 Retrieved 2014 10 17 a b c Emex australis in Flora of North America efloras org www efloras org Retrieved 2020 07 06 a b Weeds Australia Profile Emex australis profiles ala org au Retrieved 2020 07 11 Parsons W T amp Cuthbertson E G 2001 Noxious weeds of Australia Victoria CSIRO Publishing a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link External links editJepson Manual Treatment Distribution map showing where it is native and where introduced Rumex hypogaeus occurrence data from GBIF Emex australis Profile photo gallery distribution nbsp This Polygonaceae article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Rumex hypogaeus amp oldid 1176194296, wikipedia, wiki, book, books, library,
