Ononis
Ononis is a genus of 80–90 species of perennial herbs and subshrubs in the legume family Fabaceae. The members of this genus are called restharrows; an old spelling "wrestharrows" is also recorded from 1965. as some species grow as weeds on arable lands where their tough roots would catch and stop the harrow. The genus is native to Europe, northern and eastern Africa, and western and central Asia.
In herbalism restharrow is used to treat bladder and kidney problems and water retention.
The active ingredients in restharrow are essential oils, flavonoid-glycosides, and tannins.
Restharrows are used as food plants by the larvae of some Lepidoptera species including the grey pug and Coleophora ononidella.
Species of ''Ononis''
[Image:Ononis arvensis.jpeg|thumb|right|225px|O. arvensis][Image:Ononis natrix0.jpg|thumb|right|225px|Ononis natrix, flowers and foliage]
The genus Ononis includes the following species accepted by the Plants of the World Online database, with the addition of one species accepted by the Botanical Society of [Britain and Ireland] and others :Ononis adenotricha Boiss.Ononis afghanica Širj. & Rech.f.Ononis alba Poir.Ononis alopecuroides L. — foxtail restharrowOnonis angustissima Lam.Ononis antennata PomelOnonis aragonensis AssoOnonis arvensis L. — field restharrow Ononis atlantica BallOnonis aurasiaca Förther & PodlechOnonis avellana PomelOnonis azcaratei DevesaOnonis baetica ClementeOnonis basiadnata Hub.-Mor.Ononis biflora Desf.Ononis broteroana Ser.Ononis catalinae Reyes-Bet. & S.ScholzOnonis cephalantha PomelOnonis cephalotes Boiss.Ononis christii BolleOnonis cintrana Brot.Ononis clausonis PomelOnonis cossoniana Boiss. & Reut.Ononis cossoniana Boiss. & Reut.Ononis costae MenezesOnonis crinita PomelOnonis crispa L.Ononis cristata Mill.Ononis cuatrecasasii DevesaOnonis dentata Sol. ex LoweOnonis diffusa Ten.Ononis euphrasiifolia Desf.Ononis filicaulis Salzm. ex Boiss.Ononis fruticosa L.Ononis gines-lopezii DevesaOnonis hebecarpa Webb & Berthel.Ononis hirta Desf. ex Poir.Ononis hispida Desf.Ononis incisa Coss. & Durieu ex Batt.Ononis intermedia C.A.Mey. ex RouyOnonis jahandiezii Maire & WeillerOnonis laxiflora Desf.Ononis leucotricha Coss.Ononis macrosperma Hub.-Mor.Ononis maweana BallOnonis megalostachys MunbyOnonis minutissima L.Ononis mitissima L.Ononis mogadorensis Förther & PodlechOnonis natrix L. — large yellow restharrowOnonis nuristanica PodlechOnonis oligophylla Ten.Ononis ornithopodioides L.Ononis pedicellaris Širj.Ononis pendula Desf.Ononis peyerimhoffii Batt.Ononis phyllocephala Boiss.Ononis pinnata Brot.Ononis polyphylla BallOnonis polysperma Barratte & Murb.Ononis pseudoserotina Batt. & Pit.Ononis pubescens L.Ononis pusilla L.Ononis ramosissima Desf.Ononis reclinata L. — small restharrowOnonis repens L. — common restharrowOnonis reuteri Boiss.Ononis rosea DurieuOnonis rotundifolia L.Ononis serotina PomelOnonis serrata Forssk.Ononis sessilifolia Bornm.Ononis sicula Guss.Ononis sieberi Besser ex DC.Ononis speciosa Lag.Ononis spinosa L. — spiny restharrowOnonis striata GouanOnonis talaverae Devesa & G.LópezOnonis tazaensis Förther & PodlechOnonis thomsonii Ball ex Oliv.Ononis tournefortii Coss.Ononis tridentata L.Ononis unifoliolata Dobignard, Jacquemoud & Jeanm.Ononis varelae DevesaOnonis variegata L.Ononis verae Širj.Ononis villosissima Desf.Ononis viscosa L.Ononis zygantha Maire & Wilczek
The status of Ononis repens is disputed; POWO treats it as a subspecies of O. spinosa, while accepting O. arvensis as a separate species. However, in genetic analysis, O. repens recovered as more closely related to O. arvensis, than to O. spinosa. It remains widely accepted as a species, particularly in Great Britain and Ireland, where it is the most widespread and abundant species in the genus.