The Plant List — A working list for all plant species

⚠ Version 1 of The Plant List has been superseded.

You should refer instead to the current version of The Plant List.

Results

No plant names match your search for Opuntia ×deserta; we will try Opuntia instead.

1170 plant name records match your search criteria Opuntia. The results are below.

• Genus Opuntia is in the family Cactaceae. Species epithets begin with: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

The results can also be downloaded as a CSV file.

See "Status", "Confidence level", "Source" for definitions.

Name	Status	Confi­dence level	Source
Opuntia abjecta Small ex Britton & Rose	Synonym		TRO
Opuntia abyssi Hester	Synonym		WCSP (in review)
Opuntia acanthocarpa Engelm. & J.M.Bigelow	Synonym		WCSP (in review)
Opuntia acanthocarpa var. coloradensis L.D. Benson	Synonym		TRO
Opuntia acanthocarpa subsp. ganderi C.B.Wolf	Synonym		WCSP (in review)
Opuntia acanthocarpa var. ganderi (C.B. Wolf) L.D. Benson	Synonym		TRO
Opuntia acanthocarpa var. major (Engelm. & J.M. Bigelow) L.D. Benson	Synonym		TRO
Opuntia acanthocarpa var. ramosa Peebles	Synonym		TRO
Opuntia acanthocarpa var. thornberi (Thornber & Bonker) L.D. Benson	Synonym		TRO
Opuntia acaulis Ekman & Werderm.	Unresolved		WCSP (in review)
Opuntia aciculata Griffiths	Synonym		TRO
Opuntia acracantha Walp.	Unresolved		WCSP (in review)
Opuntia aequatorialis Britton & Rose	Accepted		TRO
Opuntia affinis Griffiths	Synonym		TRO
Opuntia aggeria Ralston & Hilsenb.	Synonym		TRO
Opuntia agglomerata A. Berger	Synonym		TRO
Opuntia airampo Phil.	Unresolved		WCSP (in review)
Opuntia alamosensis Britton & Rose	Synonym		TRO
Opuntia albicans Salm-Dyck	Unresolved		WCSP (in review)
Opuntia albiflora K. Schum.	Synonym		TRO
Opuntia albisaetacens Backeb.	Synonym		TRO
Opuntia albisetosa Hildm. ex Hirscht	Unresolved		WCSP (in review)
Opuntia albispinosa Mieckley ex Lindemuth & Dams	Unresolved		WCSP (in review)
Opuntia alcahes F.A.C.Weber	Synonym		WCSP (in review)
Opuntia alcerrecensis Iliff	Unresolved		WCSP (in review)
Opuntia alexanderi Britton & Rose	Synonym		TRO
Opuntia alfagayucca Karw. ex Salm-Dyck	Unresolved		WCSP (in review)
Opuntia alko-tuna Cárdenas	Synonym		TRO
Opuntia allairei Griffiths	Synonym		TRO
Opuntia alpicola K.Schum. ex Dams	Unresolved		WCSP (in review)
Opuntia alta Griffiths	Synonym		TRO
Opuntia altomagdalenensis Xhonneux	Unresolved		WCSP (in review)
Opuntia amarilla Griffiths	Unresolved		WCSP (in review)
Opuntia ambigua Link ex Ten.	Unresolved		WCSP (in review)
Opuntia ammophila Small	Synonym		TRO
Opuntia amyclaea Ten.	Synonym		TRO
Opuntia anacantha Speg.	Accepted		TRO
Opuntia anacantha var. utkilio (Speg.) R. Kiesling	Accepted		TRO
Opuntia anahuacensis Griffiths	Synonym		TRO
Opuntia × andersonii H.M.Hern., Gómez-Hin. & Bárcenas	Unresolved		WCSP (in review)
Opuntia andicola Pfeiff.	Synonym		TRO
Opuntia angusta Meinsh.	Unresolved		WCSP (in review)
Opuntia angustata Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia angustata var. comonduensis J.M. Coult.	Synonym		TRO
Opuntia anteojoensis Pinkava	Synonym		WCSP (in review)
Opuntia antillana Britton & Rose	Synonym		TRO
Opuntia aoracantha Lem.	Synonym		TRO
Opuntia apurimacensis (F. Ritter) R. Crook & Mottram	Accepted		TRO
Opuntia aquosa F.A.C.Weber	Synonym		WCSP (in review)
Opuntia araucana (A.Cast.) Kiessling	Unresolved		WCSP (in review)
Opuntia arborea Rojas Acosta	Unresolved		WCSP (in review)
Opuntia arborea Steud.	Unresolved		WCSP (in review)
Opuntia arborescens Engelm.	Synonym		TRO
Opuntia arborescens var. versicolor (Engelm. ex J.M. Coult.) Dams	Synonym		TRO
Opuntia arbuscula Engelm.	Synonym		WCSP (in review)
Opuntia arcei Cárdenas	Synonym		TRO
Opuntia archiconoidea (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia arechavaletae Speg.	Unresolved		WCSP (in review)
Opuntia arenaria Engelm.	Accepted		TRO
Opuntia argentina Griseb.	Synonym		TRO
Opuntia arizonica Griffiths	Unresolved		WCSP (in review)
Opuntia arkansana Engelm. ex Hirscht	Unresolved		WCSP (in review)
Opuntia armata Backeb.	Synonym		TRO
Opuntia armata var. panellana Backeb.	Synonym		TRO
Opuntia arrastradillo Backeb.	Accepted		TRO
Opuntia articulata (Pfeiff.) D.R. Hunt	Accepted		TRO
Opuntia asplundii (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia assumptionis K. Schum.	Accepted		TRO
Opuntia atacamensis Phil.	Unresolved		WCSP (in review)
Opuntia atrispina Griffiths	Accepted		TRO
Opuntia atrocapensis Small	Unresolved		WCSP (in review)
Opuntia atroglobosa (Backeb. ex F. Ritter) R. Crook & Mottram	Accepted		TRO
Opuntia atropes Rose	Accepted		TRO
Opuntia atrovirens Speg.	Unresolved		WCSP (in review)
Opuntia atroviridis Werderm. & Backeb.	Synonym		TRO
Opuntia auberi Pfeiff.	Accepted		TRO
Opuntia aulacothele F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia aurantiaca Lindl.	Accepted		TRO
Opuntia aurea E.M. Baxter	Accepted		TRO
Opuntia aureispina (S. Brack & K.D. Heil) Pinkava & B.D. Parfitt	Accepted		TRO
Opuntia australis F.A.C.Weber	Synonym		WCSP (in review)
Opuntia austrina Small	Synonym		TRO
Opuntia ayrampo (Azara) Mottram	Unresolved		WCSP (in review)
Opuntia azurea Rose	Accepted		TRO
Opuntia backebergii G.D. Rowley	Synonym		TRO
Opuntia bahamana Britton & Rose	Unresolved		WCSP (in review)
Opuntia bahiensis Britton & Rose	Synonym		TRO
Opuntia bakeri Madsen	Accepted		TRO
Opuntia balearica F.A.C.Weber ex Hirscht	Unresolved		WCSP (in review)
Opuntia ballii Rose	Synonym		TRO
Opuntia barbata K.Brandegee ex J.A.Purpus	Unresolved		WCSP (in review)
Opuntia barkleyana (Daston) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia bartramii Raf.	Unresolved		WCSP (in review)
Opuntia basilaris Engelm. & J.M. Bigelow	Accepted		TRO
Opuntia basilaris var. aurea (E.M. Baxter) W.T. Marshall	Synonym		TRO
Opuntia basilaris var. basilaris	Accepted		TRO
Opuntia basilaris var. brachyclada (Griffiths) Munz	Synonym		TRO
Opuntia basilaris var. humistrata (Griffiths) W.T. Marshall	Synonym		TRO
Opuntia basilaris var. longiareolata (Clover & Jotter) L.D. Benson	Accepted		TRO
Opuntia basilaris var. ramosa Parish	Synonym		TRO
Opuntia basilaris var. treleasei (J.M. Coult.) J.M. Coult. ex Toumey	Accepted		TRO
Opuntia basilaris subsp. whitneyana (E.M. Baxter) Munz	Accepted		TRO
Opuntia basilaris var. whitneyana (E.M. Baxter) W.T. Marshall & T.M. Bock	Synonym		TRO
Opuntia beckeriana K.Schum.	Unresolved		WCSP (in review)
Opuntia bella Britton & Rose	Unresolved		WCSP (in review)
Opuntia bensonii Sánchez-Mej.	Accepted		TRO
Opuntia bentonii Griffiths	Unresolved		WCSP (in review)
Opuntia bergeriana F.A.C.Weber ex A.Berger	Synonym		WCSP (in review)
Opuntia bernardina Engelm. ex Parish	Synonym		TRO
Opuntia berteroi (Colla) A.E.Hoffm.	Unresolved		WCSP (in review)
Opuntia bicolor Phil.	Synonym		TRO
Opuntia bigelovii Engelm.	Synonym		WCSP (in review)
Opuntia bigelovii var. ciribe W.T. Marshall	Synonym		TRO
Opuntia bigelovii var. hoffmannii Fosberg	Synonym		WCSP (in review)
Opuntia bisetosa Pittier	Accepted		WCSP (in review)
Opuntia bispinosa Backeb.	Synonym		TRO
Opuntia blakeana Rose	Unresolved		WCSP (in review)
Opuntia blancii (Backeb.) G.D. Rowley	Accepted		TRO
Opuntia boldinghii Britton & Rose	Accepted		WCSP (in review)
Opuntia boliviana Salm-Dyck	Synonym		TRO
Opuntia boliviensis Backeb.	Synonym		TRO
Opuntia bonaerensis Speg.	Unresolved		WCSP (in review)
Opuntia bonnieae (D.J.Ferguson & R.Kiesling) Halda & Janeba	Unresolved		WCSP (in review)
Opuntia bonplandii (Kunth) F.A.C. Weber	Accepted		TRO
Opuntia borinquensis Britton & Rose	Unresolved		WCSP (in review)
Opuntia brachyacantha (F.Ritter) R.Crook & Mottram	Unresolved		WCSP (in review)
Opuntia brachyarthra Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia brachyclada Griffiths	Synonym		TRO
Opuntia brachyclada subsp. humistrata (Griffiths) Wiggins & C.B. Wolf	Unresolved		TRO
Opuntia brachydelphis K.Schum.	Unresolved		WCSP (in review)
Opuntia brachyrhopalica (Daston) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia bradleyi G.D. Rowley	Synonym		TRO
Opuntia bradtiana (J.M. Coult.) K. Brandegee	Synonym		TRO
Opuntia brandegeei K. Schum.	Synonym		TRO
Opuntia brasiliensis (Willd.) Haw.	Synonym		TRO
Opuntia brasiliensis subsp. bahiensis (Britton & Rose) P.J. Braun & Esteves	Unresolved		TRO
Opuntia brasiliensis subsp. subacarpa (Rizzini & A. Mattos) Braun & Esteves	Synonym		TRO
Opuntia bravoana Baxter	Accepted		TRO
Opuntia brevispina Gates	Synonym		TRO
Opuntia brittonii J.G. Ortega	Synonym		TRO
Opuntia bruchii Speg.	Synonym		TRO
Opuntia brunneogemmia (F.Ritter) Schlindw.	Unresolved		WCSP (in review)
Opuntia brunnescens Britton & Rose	Unresolved		WCSP (in review)
Opuntia bulbispina Engelm.	Synonym		TRO
Opuntia burrageana Britton & Rose	Synonym		TRO
Opuntia cacanapa Griffiths & Hare	Synonym		TRO
Opuntia caerulescens Griffiths	Synonym		TRO
Opuntia caesia Griffiths	Unresolved		WCSP (in review)
Opuntia calacantha Forbes ex W.H.Baxter	Unresolved		WCSP (in review)
Opuntia calantha Griffiths	Unresolved		WCSP (in review)
Opuntia calcicola Wherry	Synonym		TRO
Opuntia californica Engelm.	Synonym		TRO
Opuntia californica (Torr. & A. Gray) Coville	Synonym		TRO
Opuntia californica var. parkeri (J.M. Coult.) Pinkava	Synonym		TRO
Opuntia calmalliana J.M. Coult.	Synonym		TRO
Opuntia calva Lem.	Unresolved		WCSP (in review)
Opuntia camachoi Espinosa	Unresolved		WCSP (in review)
Opuntia camanchica Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia campestris Britton & Rose	Synonym		TRO
Opuntia × campii M.A. Baker & Pinkava	Synonym		TRO
Opuntia camuessa F.A.C. Weber	Synonym		TRO
Opuntia canada Griffiths	Unresolved		WCSP (in review)
Opuntia candelabriformis hort. ex Pfeiff.	Synonym		TRO
Opuntia canina Speg.	Synonym		TRO
Opuntia cantabrigiensis Lynch	Accepted		TRO
Opuntia canterae Arechav.	Unresolved		WCSP (in review)
Opuntia caracassana Salm-Dyck	Accepted		WCSP (in review)
Opuntia cardenche Griffiths	Synonym		TRO
Opuntia cardiosperma K.Schum.	Unresolved		WCSP (in review)
Opuntia cardona F.A.C. Weber	Synonym		TRO
Opuntia caribaea Britton & Rose	Synonym		WCSP (in review)
Opuntia carnosa A.Usteri	Unresolved		WCSP (in review)
Opuntia carolina J.Forbes	Unresolved		WCSP (in review)
Opuntia × carstenii R.Puente & C.Hamann	Unresolved		WCSP (in review)
Opuntia castillae Griffiths	Synonym		TRO
Opuntia catingicola Werderm.	Synonym		TRO
Opuntia catocantha Pfeiff.	Unresolved		WCSP (in review)
Opuntia cedergreniana Backeb.	Unresolved		WCSP (in review)
Opuntia cereiformis F.A.C. Weber	Synonym		TRO
Opuntia × cervicornis Späth	Unresolved		WCSP (in review)
Opuntia cespitosa Raf.	Unresolved		WCSP (in review)
Opuntia chaetocarpa Griffiths	Unresolved		WCSP (in review)
Opuntia chaffeyi Britton & Rose	Accepted		TRO
Opuntia chakensis Speg.	Synonym		TRO
Opuntia chapistle F.A.C. Weber	Synonym		TRO
Opuntia charlestonensis Clokey	Unresolved		WCSP (in review)
Opuntia chata Griffiths	Unresolved		WCSP (in review)
Opuntia chavena Griffiths	Synonym		TRO
Opuntia chiangiana Scheinvar & Manzanero	Unresolved		TRO
Opuntia chichensis (Cárdenas) G.D. Rowley	Synonym		TRO
Opuntia chichensis var. colchana (Cárdenas) G.D. Rowley	Synonym		TRO
Opuntia chihuahuensis Rose	Synonym		TRO
Opuntia chilensis (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia chinensis (Roxb.) K. Koch	Synonym		TRO
Opuntia chisosensis (M.S. Anthony) D.J. Ferguson	Synonym		TRO
Opuntia chlorotica Engelm. & J.M. Bigelow	Accepted		TRO
Opuntia chlorotica var. santarita Griffiths & Hare	Synonym		TRO
Opuntia cholla F.A.C.Weber	Synonym		WCSP (in review)
Opuntia chuquisacana Cárdenas	Synonym		TRO
Opuntia cineracea Wiggins	Synonym		TRO
Opuntia ciribe Engelm.	Synonym		TRO
Opuntia clavarioides Pfeiff.	Synonym		TRO
Opuntia clavata Engelm.	Synonym		TRO
Opuntia clavellina Engelm. ex J.M. Coult.	Synonym		TRO
Opuntia coccinea Pfeiff.	Unresolved		WCSP (in review)
Opuntia coccinellifera Steud.	Unresolved		WCSP (in review)
Opuntia cochabambensis Cárdenas	Synonym		TRO
Opuntia cochenillifera (L.) Mill.	Synonym		TRO
Opuntia cochinelifera (L.) Mill.	Synonym		WCSP (in review)
Opuntia × cochinera Griffiths	Accepted		TRO
Opuntia coerulea Gillies ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia cognata (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia coindetti F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia colorea (F. Ritter) D.R. Hunt	Accepted		TRO
Opuntia colubrina A. Cast.	Accepted		TRO
Opuntia × columbiana Griffiths (pro sp.)	Accepted		TRO
Opuntia comonduensis (J.M. Coult.) Britton & Rose	Synonym		TRO
Opuntia compressa J.F. Macbr.	Synonym		TRO
Opuntia compressa var. allairei (Griffiths) Weniger	Unresolved		TRO
Opuntia compressa var. ammophila (Small) L.D. Benson	Synonym		TRO
Opuntia compressa var. austrina (Small) L.D. Benson	Synonym		TRO
Opuntia compressa var. fuscoatra (Engelm.) Weniger	Synonym		TRO
Opuntia compressa var. macrorhiza (Engelm.) L.D. Benson	Synonym		TRO
Opuntia compressa var. stenochila (Engelm. & J.M. Bigelow) Weniger	Unresolved		TRO
Opuntia confusa Griffiths	Unresolved		WCSP (in review)
Opuntia × congesta Griffiths	Synonym		WCSP (in review)
Opuntia conjungens (F. Ritter) P.J. Braun & Esteves	Synonym		TRO
Opuntia conoidea (F. Ritter) G.D. Rowley	Synonym		TRO
Opuntia convexa Mackensen	Unresolved		WCSP (in review)
Opuntia corallicola (Small) Werderm.	Synonym		TRO
Opuntia cordobensis Speg.	Synonym		TRO
Opuntia corotilla K. Schum. ex Vaupel	Accepted		TRO
Opuntia corotilla var. aurantiaciflora (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia corrugata Salm-Dyck	Unresolved		WCSP (in review)
Opuntia costigera Miq.	Unresolved		WCSP (in review)
Opuntia covillei Britton & Rose	Synonym		TRO
Opuntia crassa Haw.	Accepted		TRO
Opuntia crassicylindrica (Rauh & Backeb.) G.D. Rowley	Accepted		TRO
Opuntia crassispina (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia cretochaeta Griffiths	Synonym		TRO
Opuntia crinifera Salm-Dyck ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia crispicrinita (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia crispicrinita var. cylindracea (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia cruciata Pfeiff.	Unresolved		WCSP (in review)
Opuntia crystalenia Griffiths	Accepted		TRO
Opuntia cubensis Britton & Rose	Accepted		TRO
Opuntia cucumiformis Griffiths	Unresolved		WCSP (in review)
Opuntia cuija (Griffiths & Hare) Britton & Rose	Synonym		TRO
Opuntia cumulicola Small	Unresolved		WCSP (in review)
Opuntia curassavica (L.) Mill.	Accepted		WCSP (in review)
Opuntia × curvispina Griffiths	Unresolved		WCSP (in review)
Opuntia curvospina Griffiths	Unresolved		WCSP (in review)
Opuntia cyanea Griffiths	Unresolved		WCSP (in review)
Opuntia cyanella Griffiths	Unresolved		WCSP (in review)
Opuntia cyclodes (Engelm. & J.M. Bigelow) Rose	Accepted		TRO
Opuntia cylindrarticulata (Cárdenas) G.D. Rowley	Synonym		TRO
Opuntia cylindrica (Lam.) DC.	Accepted		TRO
Opuntia cylindrolanata (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia cymochila Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia dactylifera Vaupel	Synonym		TRO
Opuntia darrahiana F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia darwinii Hensl.	Synonym		WCSP (in review)
Opuntia davisii Engelm. & J.M.Bigelow	Synonym		WCSP (in review)
Opuntia deamii Rose	Accepted		TRO
Opuntia debreczyi Szutorisz	Unresolved		WCSP (in review)
Opuntia decipiens DC.	Unresolved		WCSP (in review)
Opuntia decumana (Willd.) Haw.	Synonym		TRO
Opuntia decumbens Salm-Dyck	Accepted		WCSP (in review)
Opuntia decumbens var. scheinvariana E. Paniagua	Synonym		TRO
Opuntia deflexa Lem.	Unresolved		WCSP (in review)
Opuntia dejecta Salm-Dyck	Synonym		WCSP (in review)
Opuntia delaetiana (F.A.C. Weber) Vaupel	Accepted		TRO
Opuntia delicata Rose	Synonym		TRO
Opuntia demissa Griffiths	Unresolved		WCSP (in review)
Opuntia demorenia Forbes	Unresolved		WCSP (in review)
Opuntia demoriana C.F.Först.	Unresolved		WCSP (in review)
Opuntia densiaculeata (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia densispina Ralston & Hilsenb.	Synonym		TRO
Opuntia denudata F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia depauperata Britton & Rose	Synonym		WCSP (in review)
Opuntia deppei H.L.Wendl. ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia depressa Rose	Accepted		TRO
Opuntia × deserta Griffiths	Synonym		WCSP (in review)
Opuntia diademata Lem.	Synonym		TRO
Opuntia diademata var. oligacantha Speg.	Synonym		TRO
Opuntia dichotoma J.Forbes	Unresolved		WCSP (in review)
Opuntia diffusa Pfeiff.	Unresolved		WCSP (in review)
Opuntia digitalis F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia diguetii F.A.C.Weber	Synonym		WCSP (in review)
Opuntia dillei Griffiths	Synonym		TRO
Opuntia dillenii (Ker Gawl.) Haw.	Accepted		TRO
Opuntia dillenii var. tehuantepecana Bravo	Synonym		TRO
Opuntia dimorpha Foerster	Synonym		TRO
Opuntia diplacantha A.Berger	Unresolved		WCSP (in review)
Opuntia discata Griffiths	Synonym		TRO
Opuntia discolor Britton & Rose	Accepted		TRO
Opuntia distans Britton & Rose	Synonym		TRO
Opuntia diversispina Griffiths	Unresolved		WCSP (in review)
Opuntia dobbieana Britton & Rose	Synonym		TRO
Opuntia dolabriformis Pfeiff.	Unresolved		WCSP (in review)
Opuntia domeykoensis (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia domingensis Britton & Rose	Unresolved		WCSP (in review)
Opuntia drummondii Graham	Synonym		TRO
Opuntia dulcis Engelm.	Synonym		TRO
Opuntia dumetorum A. Berger	Synonym		TRO
Opuntia durangensis Britton & Rose	Accepted		TRO
Opuntia duvalioides (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia eborina C.F.Först. ex Haage	Unresolved		WCSP (in review)
Opuntia eburnea Lem.	Unresolved		WCSP (in review)
Opuntia eburnispina Small ex Britton & Rose	Unresolved		WCSP (in review)
Opuntia echinacea (F.Ritter) A.E.Hoffm.	Unresolved		WCSP (in review)
Opuntia echinocarpa Engelm. & J.M.Bigelow	Synonym		WCSP (in review)
Opuntia echinocarpa var. major Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia echinocarpa var. nuda J.M. Coult.	Synonym		TRO
Opuntia echinocarpa var. parkeri J.M. Coult.	Synonym		TRO
Opuntia echinocarpa var. robustior J.M. Coult.	Synonym		TRO
Opuntia echinocarpa var. wolfii L.D.Benson	Synonym		WCSP (in review)
Opuntia echios Howell	Accepted		TRO
Opuntia echios var. echios	Accepted		TRO
Opuntia echios var. gigantea Howell	Accepted		TRO
Opuntia echios var. prolifera E.Y. Dawson	Synonym		TRO
Opuntia echios var. zacana (Howell) E.F. Anderson & Walk.	Accepted		TRO
Opuntia edwardsii V.E.Grant & K.A.Grant	Unresolved		WCSP (in review)
Opuntia effulgia Griffiths	Unresolved		WCSP (in review)
Opuntia eichlamii Rose	Accepted		TRO
Opuntia ekmanii Werderm.	Unresolved		WCSP (in review)
Opuntia elata Link & Otto ex Salm-Dyck	Accepted		TRO
Opuntia elata var. delaitiana F.A.C. Weber	Synonym		TRO
Opuntia elatior Mill.	Accepted		WCSP (in review)
Opuntia × elisae D.Guillot & P.Van der Meer	Unresolved		WCSP (in review)
Opuntia elizondoana E. Sanchez M. & Villasenor	Accepted		TRO
Opuntia ellemeetiana Miq.	Synonym		TRO
Opuntia ellisiana Griffiths	Accepted		TRO
Opuntia elongata Haw.	Unresolved		WCSP (in review)
Opuntia emoryi Engelm.	Synonym		TRO
Opuntia engelmannii Salm-Dyck	Accepted		TRO
Opuntia engelmannii subsp. aciculata (Griffiths) U. Guzmán & Mandujano	Accepted		TRO
Opuntia engelmannii var. aciculata (Griffiths) Weniger	Synonym		TRO
Opuntia engelmannii var. aciculata (Griffiths) Bravo	Synonym		TRO
Opuntia engelmannii var. alta (Griffiths) Weniger	Synonym		TRO
Opuntia engelmannii var. cacanapa (Griffiths & Hare) Weniger	Synonym		TRO
Opuntia engelmannii var. cuija Griffiths & Hare	Synonym		TRO
Opuntia engelmannii var. cyclodes Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia engelmannii var. discata (Griffiths) A. Nelson	Synonym		TRO
Opuntia engelmannii var. dulcis (Engelm.) J.M. Coult. ex K. Schum.	Accepted		TRO
Opuntia engelmannii subsp. engelmannii	Unresolved		TRO
Opuntia engelmannii var. engelmannii	Accepted		TRO
Opuntia engelmannii var. flavescens (Peebles) L.D. Benson	Accepted		TRO
Opuntia engelmannii var. flexospina (Griffiths) B.D. Parfitt & Pinkava	Accepted		TRO
Opuntia engelmannii subsp. lindheimeri (Engelm.) U. Guzmán & Mandujano	Accepted		TRO
Opuntia engelmannii var. lindheimeri (Engelm.) B.D. Parfitt & Pinkava	Synonym		TRO
Opuntia engelmannii var. linguiformis (Griffiths) B.D. Parfitt & Pinkava	Accepted		TRO
Opuntia engelmannii var. littoralis Engelm.	Synonym		TRO
Opuntia engelmannii var. megacarpa (Griffiths) Fosberg	Synonym		TRO
Opuntia engelmannii var. subarmata (Griffiths) Weniger	Synonym		TRO
Opuntia engelmannii var. texana (Griffiths) Weniger	Synonym		TRO
Opuntia engelmannii var. wootonii (Griffiths) Fosberg	Synonym		TRO
Opuntia eocarpa Griffiths	Unresolved		WCSP (in review)
Opuntia erecta K.Schum.	Unresolved		WCSP (in review)
Opuntia erectoclada Backeb.	Unresolved		WCSP (in review)
Opuntia erinacea Engelm. & J.M. Bigelow	Accepted		TRO
Opuntia erinacea var. aurea (E.M. Baxter) S.L. Welsh	Synonym		TRO
Opuntia erinacea var. columbiana (Griffiths (pro sp.)) L.D. Benson	Synonym		TRO
Opuntia erinacea var. hystricina (Engelm. & J.M. Bigelow) L.D. Benson	Synonym		TRO
Opuntia erinacea var. rhodantha (K. Schum.) L.D. Benson	Synonym		TRO
Opuntia erinacea var. ursina (F.A.C. Weber) Parish	Synonym		TRO
Opuntia erinacea var. utahensis (Engelm.) L.D. Benson	Accepted		TRO
Opuntia erinacea var. xanthostemma (K. Schum.) L.D. Benson	Synonym		TRO
Opuntia erythrocentron Lem. ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia estevesii P.J.Braun	Unresolved		WCSP (in review)
Opuntia exaltata A. Berger	Synonym		TRO
Opuntia excelsa Sánchez-Mej.	Accepted		TRO
Opuntia expansa Griffiths	Unresolved		WCSP (in review)
Opuntia extensa Salm-Dyck ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia exuviata DC.	Unresolved		WCSP (in review)
Opuntia exuviata Salm-Dyck	Unresolved		WCSP (in review)
Opuntia exuviata var. stellata (Salm-Dyck) Lem. ex Labour.	Unresolved		TRO
Opuntia exuviatostellata Lem. ex Labour.	Unresolved		WCSP (in review)
Opuntia falcata Ekman & Werderm.	Unresolved		WCSP (in review)
Opuntia feroacantha Rose ex J.G. Ortega	Accepted		TRO
Opuntia ferocior (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia ferox Haw.	Unresolved		WCSP (in review)
Opuntia ferruginispina Griffiths	Unresolved		WCSP (in review)
Opuntia festiva Sencke ex Haage	Unresolved		WCSP (in review)
Opuntia ficus-barbarica A.Berger	Unresolved		WCSP (in review)
Opuntia ficus-indica (L.) Mill.	Accepted		WCSP (in review)
Opuntia ficus-indica var. decumana (Haw.) Speg.	Accepted		TRO
Opuntia ficus-indica var. gymnocarpa (F.A.C. Weber) Speg.	Accepted		TRO
Opuntia ficus-indica x soederstromiana	Accepted		TRO
Opuntia filipendula Engelm.	Synonym		TRO
Opuntia flavescens Peebles	Synonym		TRO
Opuntia flavicans Lem.	Unresolved		WCSP (in review)
Opuntia flavispina C.F.Först.	Unresolved		WCSP (in review)
Opuntia flexibilis Pfeiff.	Unresolved		WCSP (in review)
Opuntia flexospina Griffiths	Synonym		TRO
Opuntia flexuosa (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia floccosa Salm-Dyck	Synonym		TRO
Opuntia floccosa var. crassior (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia floccosa var. ovoides (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia floribunda Lem.	Unresolved		WCSP (in review)
Opuntia foliosa Salm-Dyck ex DC.	Unresolved		WCSP (in review)
Opuntia formidabilis Walton	Unresolved		WCSP (in review)
Opuntia × fosbergii C.B.Wolf	Synonym		WCSP (in review)
Opuntia fragilis (Nutt.) Haw.	Accepted		WCSP (in review)
Opuntia fragilis var. brachyarthra (Engelm. & J.M. Bigelow) J.M. Coult.	Synonym		TRO
Opuntia fragilis var. frutescens Engelm. & A. Gray	Synonym		TRO
Opuntia frigida (F. Ritter) G. Navarro	Synonym		TRO
Opuntia frustulenta Gibbes	Unresolved		WCSP (in review)
Opuntia frutescens Engelm.	Synonym		TRO
Opuntia frutescens var. brevispina Engelm.	Synonym		TRO
Opuntia frutescens var. longispina Engelm.	Synonym		TRO
Opuntia fulgens Engelm.	Unresolved		WCSP (in review)
Opuntia fulgida Engelm.	Synonym		WCSP (in review)
Opuntia fulgida var. hoffmannii (Fosberg) L.D. Benson	Synonym		TRO
Opuntia fulgida var. mamillata (Schott ex Engelm.) J.M. Coult.	Synonym		TRO
Opuntia fuliginosa Griffiths	Accepted		TRO
Opuntia fulvicoma (Rauh & Backeb.) G.D. Rowley	Accepted		TRO
Opuntia fulvicoma var. bicolor (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia fulvispina Salm-Dyck ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia funalis (Britton & Rose) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia furiosa H.L.Wendl.	Unresolved		WCSP (in review)
Opuntia fuscoatra Engelm.	Synonym		TRO
Opuntia fuscolineata Starm. & Mucher	Unresolved		WCSP (in review)
Opuntia fusicaulis Griffiths	Unresolved		WCSP (in review)
Opuntia fusiformis Engelm. & J.M.Bigelow	Unresolved		WCSP (in review)
Opuntia galapageia Hemsl.	Accepted		TRO
Opuntia galapageia var. echios Backeb.	Synonym		TRO
Opuntia galapageia var. gigantea Backeb.	Synonym		TRO
Opuntia galapageia var. helleri Backeb.	Synonym		TRO
Opuntia galapageia var. insularis Backeb.	Synonym		TRO
Opuntia galapageia var. myriacantha Backeb.	Synonym		TRO
Opuntia galapageia var. saxicola Backeb.	Synonym		TRO
Opuntia galapageia var. zacana Backeb.	Synonym		TRO
Opuntia galeottii De Smet ex Miq.	Unresolved		WCSP (in review)
Opuntia galerasensis (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia ganderi (C.B. Wolf) Rebman & Pinkava	Synonym		TRO
Opuntia geissei Phil.	Unresolved		WCSP (in review)
Opuntia geometrica A. Cast.	Synonym		TRO
Opuntia gilliesii Pfeiff.	Unresolved		WCSP (in review)
Opuntia gilvescens Griffiths	Unresolved		WCSP (in review)
Opuntia gilvoalba Griffiths	Unresolved		WCSP (in review)
Opuntia glaberrima Pfeiff.	Unresolved		WCSP (in review)
Opuntia glauca Pfeiff.	Unresolved		WCSP (in review)
Opuntia glaucescens Salm-Dyck	Synonym		TRO
Opuntia glaucophylla H.L.Wendl. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia glomerata Haw.	Synonym		TRO
Opuntia golziana K. Schum.	Synonym		TRO
Opuntia gomei Griffiths	Unresolved		WCSP (in review)
Opuntia gorda Griffiths	Synonym		TRO
Opuntia gosseliniana F.A.C. Weber	Synonym		TRO
Opuntia gosseliniana var. santarita (Griffiths & Hare) L.D. Benson	Synonym		TRO
Opuntia gracilicylindrica (Wiegand & Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia gracilior Lem.	Unresolved		WCSP (in review)
Opuntia gracilis Pfeiff.	Synonym		TRO
Opuntia grahamii Engelm.	Synonym		TRO
Opuntia grandiflora Engelm.	Synonym		TRO
Opuntia grandis Pfeiff.	Accepted		TRO
Opuntia grata Phil.	Unresolved		WCSP (in review)
Opuntia greenei Britton & Rose	Unresolved		TRO
Opuntia gregoriana Griffiths	Unresolved		WCSP (in review)
Opuntia griffithsiana Mackensen	Unresolved		WCSP (in review)
Opuntia grosseiana F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia grossieana F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia guanicana Gürke	Unresolved		WCSP (in review)
Opuntia guatemalensis Britton & Rose	Unresolved		WCSP (in review)
Opuntia guatinensis D.R.Hunt	Unresolved		WCSP (in review)
Opuntia guerrana Griffiths	Synonym		TRO
Opuntia guilanchi Griffiths	Accepted		TRO
Opuntia gymnocarpa F.A.C. Weber	Synonym		TRO
Opuntia haematacantha (Backeb.) Borg	Synonym		TRO
Opuntia haematocarpa A.Berger	Unresolved		WCSP (in review)
Opuntia haitiensis Britton	Unresolved		WCSP (in review)
Opuntia halophila Speg.	Synonym		TRO
Opuntia hamiltonii (Gates) G.D. Rowley	Synonym		TRO
Opuntia hanburyana F.A.C.Weber ex A.Berger	Unresolved		WCSP (in review)
Opuntia hattoniana Britton & Rose	Unresolved		WCSP (in review)
Opuntia heacockiae Arp	Synonym		TRO
Opuntia heliabravoana Scheinvar	Synonym		TRO
Opuntia heliae Matuda	Synonym		TRO
Opuntia helleri K. Schum. ex B.L. Rob.	Accepted		TRO
Opuntia hempeliana K.Schum.	Unresolved		WCSP (in review)
Opuntia hernandezii DC.	Synonym		TRO
Opuntia herrfeldtii Kupper	Synonym		TRO
Opuntia heteromorpha Phil.	Unresolved		WCSP (in review)
Opuntia hickenii Britton & Rose	Synonym		TRO
Opuntia hieronymi Griseb.	Unresolved		WCSP (in review)
Opuntia hildemanii Frić	Synonym		TRO
Opuntia hirschii (Backeb.) G.D. Rowley	Accepted		TRO
Opuntia hispanica Griffiths	Unresolved		WCSP (in review)
Opuntia hitchcockii J.G. Ortega	Accepted		TRO
Opuntia hitchenii J.Forbes	Unresolved		WCSP (in review)
Opuntia hoffmannii Bravo	Synonym		TRO
Opuntia hondurensis Standl.	Unresolved		WCSP (in review)
Opuntia horizontalis Gillies ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia horrida Salm-Dyck ex DC.	Unresolved		WCSP (in review)
Opuntia horstii Heinrich	Unresolved		WCSP (in review)
Opuntia hossei (Krainz & Graser) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia howeyi J.A. Purpus	Accepted		TRO
Opuntia huajuapensis Bravo	Accepted		TRO
Opuntia hualpaensis Hester	Unresolved		WCSP (in review)
Opuntia humahuacana (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia humifusa (Raf.) Raf.	Accepted		TRO
Opuntia humifusa var. ammophila (Small) L.D. Benson	Synonym		TRO
Opuntia humifusa var. austrina (Small) Dress	Synonym		TRO
Opuntia humifusa var. humifusa	Accepted		TRO
Opuntia humifusa subsp. humifusa	Unresolved		TRO
Opuntia humifusa subsp. minor (Engelm.) R. Crook & Mottram	Accepted		TRO
Opuntia humifusa var. vaseyi (J.M. Coult.) A. Heller	Synonym		TRO
Opuntia humilis Haw.	Unresolved		WCSP (in review)
Opuntia humistrata Griffiths	Synonym		TRO
Opuntia hypogaea Werderm.	Synonym		TRO
Opuntia hypsophila Speg.	Synonym		TRO
Opuntia hyptiacantha F.A.C. Weber	Accepted		TRO
Opuntia hystricina Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia hystricina var. nicholii (L.D. Benson) Backeb.	Synonym		TRO
Opuntia hystricina var. ursina (F.A.C. Weber) Backeb.	Synonym		TRO
Opuntia hystrix Griseb.	Synonym		WCSP (in review)
Opuntia ianthinantha (F. Ritter) Iliff	Synonym		TRO
Opuntia icterica Griffiths	Synonym		TRO
Opuntia ignescens Vaupel	Synonym		TRO
Opuntia ignota Britton & Rose	Synonym		TRO
Opuntia imbricata (Haw.) DC.	Synonym		WCSP (in review)
Opuntia imbricata var. argentea M.S. Anthony	Synonym		TRO
Opuntia imbricata var. cardenche (Griffiths) Bravo	Synonym		TRO
Opuntia imbricata var. lloydii (Rose) Bravo	Synonym		TRO
Opuntia impedata Small	Synonym		TRO
Opuntia inaequilaterlis A. Berger	Accepted		TRO
Opuntia inamoena K.Schum.	Synonym		WCSP (in review)
Opuntia inaperta (Schott ex Griffiths) D.R. Hunt	Accepted		TRO
Opuntia incarnadilla Griffiths	Synonym		TRO
Opuntia inermis (DC.) DC.	Synonym		TRO
Opuntia infesta (F. Ritter) Iliff	Accepted		TRO
Opuntia insularis Stewart	Accepted		TRO
Opuntia intermedia Salm-Dyck	Unresolved		WCSP (in review)
Opuntia intermedia A.Gray	Unresolved		WCSP (in review)
Opuntia intricata Griffiths	Unresolved		WCSP (in review)
Opuntia invicta Brandegee	Synonym		TRO
Opuntia ipatiana Cárdenas	Synonym		TRO
Opuntia irrorata Mart. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia italica Ten. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia ithypetala Griffiths	Unresolved		WCSP (in review)
Opuntia jaliscana Bravo	Accepted		TRO
Opuntia jamaicensis Britton & Harris	Unresolved		WCSP (in review)
Opuntia joconostle F.A.C. Weber	Accepted		TRO
Opuntia juniperina Britton & Rose	Synonym		TRO
Opuntia jussieui J.N.Haage ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia karwinskiana Salm-Dyck	Accepted		TRO
Opuntia × kelvinensis V.E.Grant & K.A.Grant	Synonym		WCSP (in review)
Opuntia keyensis Britton ex Small	Unresolved		WCSP (in review)
Opuntia kiskaloro Speg.	Synonym		TRO
Opuntia kleiniae DC.	Synonym		WCSP (in review)
Opuntia kleiniae var. tetracantha (Toumey (pro sp.)) W. T. Marshall	Synonym		TRO
Opuntia kuehnrichiana Werderm. & Backeb.	Synonym		TRO
Opuntia kuehnrichiana var. applanata Werderm. & Backeb.	Synonym		TRO
Opuntia kuehnrichii Backeb.	Unresolved		WCSP (in review)
Opuntia kunzei Rose	Synonym		TRO
Opuntia kunzei var. wrightiana (E.M. Baxter) Peebles	Synonym		TRO
Opuntia labouretiana K.Schum.	Unresolved		WCSP (in review)
Opuntia laetevirens Backeb.	Unresolved		WCSP (in review)
Opuntia laevis J.M. Coult.	Synonym		TRO
Opuntia lagopus K. Schum.	Accepted		TRO
Opuntia lagopus var. aurea (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia lagopus var. aureo-penicillata (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia lagopus var. leucolagopus (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia lagopus var. pachyclada (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia lagunae Baxter ex Bravo	Accepted		TRO
Opuntia laiglonii Fric	Unresolved		WCSP (in review)
Opuntia lanceolata Haw.	Unresolved		WCSP (in review)
Opuntia lanigera Salm-Dyck	Unresolved		WCSP (in review)
Opuntia lanigera Parm. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia larreyi F.A.C. Weber ex Coult.	Synonym		TRO
Opuntia lasiacantha Pfeiff.	Accepted		TRO
Opuntia laxiflora Griffiths	Unresolved		WCSP (in review)
Opuntia ledienii A.Berger	Unresolved		WCSP (in review)
Opuntia lemaireana Console ex Bois	Unresolved		WCSP (in review)
Opuntia leoncito Werderm.	Synonym		TRO
Opuntia leonina F.Haage & M.Schmidt ex C.F.Först. & Rümpler	Unresolved		WCSP (in review)
Opuntia leptarthra F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia leptocarpa Mackensen	Unresolved		WCSP (in review)
Opuntia leptocaulis DC.	Synonym		WCSP (in review)
Opuntia leptocaulis var. badia A. Berger	Synonym		TRO
Opuntia leptocaulis var. brevispina (Engelm.) S. Watson	Synonym		TRO
Opuntia leptocaulis var. brittonii (J.G. Ortega) Bravo	Synonym		TRO
Opuntia leptocaulis var. longispina (Engelm.) A. Berger	Synonym		TRO
Opuntia leptocaulis var. pleuriseta A. Berger	Synonym		TRO
Opuntia leptocaulis var. robustior A. Berger	Synonym		TRO
Opuntia leptocaulis var. vaginata (Engelm.) S. Watson	Synonym		TRO
Opuntia leucacantha Salm-Dyck	Unresolved		WCSP (in review)
Opuntia leucantha Link & Otto ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia leucophaea Phil.	Synonym		TRO
Opuntia leucostata J.Forbes	Unresolved		WCSP (in review)
Opuntia leucosticta H.L.Wendl. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia leucotricha DC.	Accepted		TRO
Opuntia lilae Trujillo & Marisela Ponce	Accepted		WCSP (in review)
Opuntia limitata (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia lindheimeri Engelm.	Synonym		TRO
Opuntia lindheimeri var. aciculata (Griffiths) Bravo	Synonym		TRO
Opuntia lindheimeri var. chisosensis M.S. Anthony	Synonym		TRO
Opuntia lindheimeri var. cuija (Griffiths & Hare) L.D. Benson	Synonym		TRO
Opuntia lindheimeri var. cyclodes (Engelm. & J.M. Bigelow) J.M. Coult.	Synonym		TRO
Opuntia lindheimeri var. dulcis (Engelm.) J.M. Coult.	Synonym		TRO
Opuntia lindheimeri var. ellisiana (Griffiths) K. Hammer	Synonym		TRO
Opuntia lindheimeri var. lehmannii L.D. Benson	Synonym		TRO
Opuntia lindheimeri var. linguiformis (Griffiths) L.D. Benson	Synonym		TRO
Opuntia lindheimeri var. littoralis (Engelm.) J.M. Coult.	Synonym		TRO
Opuntia lindheimeri var. occidentalis (Engelm. & J. M. Bigelow (pro sp.)) J.M. Coult.	Unresolved		TRO
Opuntia lindheimeri var. subarmata (Griffiths) Elizondo & Wehbe	Synonym		TRO
Opuntia lindheimeri var. tricolor (Griffiths) L.D. Benson	Synonym		TRO
Opuntia lindsayi Rebman	Synonym		WCSP (in review)
Opuntia linguiformis Griffiths	Synonym		TRO
Opuntia littoralis (Engelm.) Britton & Rose	Unresolved		TRO
Opuntia littoralis (Engelm.) Cockerell	Accepted		TRO
Opuntia littoralis var. austrocalifornica L.D. Benson & Walk.	Synonym		TRO
Opuntia littoralis var. martiniana (L.D. Benson) L.D. Benson	Synonym		TRO
Opuntia littoralis var. piercei (Fosberg) L.D. Benson & Walk.	Accepted		TRO
Opuntia littoralis var. vaseyi (J.M. Coult.) L.D. Benson & Walk.	Synonym		TRO
Opuntia llanos-de-huanta D.R.Hunt	Unresolved		WCSP (in review)
Opuntia lloydii Rose	Synonym		TRO
Opuntia longiareolata Clover & Jotter	Synonym		TRO
Opuntia longiclada Griffiths	Unresolved		WCSP (in review)
Opuntia longiglochia C.Z.Nelson	Unresolved		WCSP (in review)
Opuntia longispina Pfeiff.	Unresolved		WCSP (in review)
Opuntia longispina Haw.	Unresolved		WCSP (in review)
Opuntia loomisii Peebles	Unresolved		WCSP (in review)
Opuntia lubrica Griffiths	Synonym		TRO
Opuntia lucayana Britton	Unresolved		WCSP (in review)
Opuntia lucens Griffiths	Synonym		TRO
Opuntia lucida auct.	Unresolved		WCSP (in review)
Opuntia lutea (Rose) D.R. Hunt	Synonym		TRO
Opuntia lutea (Rose) Solomon	Accepted		TRO
Opuntia macateei Britton & Rose	Unresolved		WCSP (in review)
Opuntia macbridei Britton & Rose	Synonym		TRO
Opuntia macbridei var. orbicularis Rauh & Backeb.	Synonym		TRO
Opuntia macdougaliana Rose	Synonym		TRO
Opuntia mackensenii Rose	Synonym		TRO
Opuntia macracantha Griseb.	Unresolved		WCSP (in review)
Opuntia macrantha Gibbes	Unresolved		WCSP (in review)
Opuntia macrocalyx Griffiths	Synonym		TRO
Opuntia macrocentra Engelm.	Accepted		TRO
Opuntia macrocentra var. aureispina S. Brack & K.D. Heil	Synonym		TRO
Opuntia macrocentra var. martiniana L.D. Benson	Synonym		TRO
Opuntia macrocentra var. minor M.S. Anthony	Synonym		TRO
Opuntia macrorhiza Engelm.	Accepted		TRO
Opuntia macrorhiza subsp. macrorhiza	Accepted		TRO
Opuntia macrorhiza subsp. potosina (Hern.-Valencia) U. Guzmán & Mandujano	Accepted		TRO
Opuntia macrorhiza var. potosina Hern.-Valencia	Synonym		TRO
Opuntia macrorhiza subsp. pottsii (Salm-Dyck) U. Guzmán & Mandujano	Accepted		TRO
Opuntia macrorhiza var. pottsii (Salm-Dyck) L.D. Benson	Synonym		TRO
Opuntia maculacantha C.F.Först.	Unresolved		WCSP (in review)
Opuntia maelenii Salm-Dyck	Unresolved		WCSP (in review)
Opuntia magenta Griffiths	Unresolved		WCSP (in review)
Opuntia magna Griffiths	Unresolved		WCSP (in review)
Opuntia magnarenensis Griffiths	Unresolved		WCSP (in review)
Opuntia magnifica Small	Unresolved		WCSP (in review)
Opuntia magnifolia Noronha	Unresolved		WCSP (in review)
Opuntia maidenii Griffiths	Unresolved		WCSP (in review)
Opuntia maihuen Gay	Synonym		TRO
Opuntia maldonadensis Arechav.	Synonym		TRO
Opuntia mamillata Schott ex Engelm.	Synonym		TRO
Opuntia mandragora (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia marenae W.E. Parsons	Synonym		TRO
Opuntia margaritana (J.M. Coult.) Baxter	Synonym		TRO
Opuntia maritima Raf.	Unresolved		WCSP (in review)
Opuntia marnieriana Backeb.	Accepted		TRO
Opuntia martiniana (L.D. Benson) B.D. Parfitt	Accepted		TRO
Opuntia matudae Scheinvar	Unresolved		WCSP (in review)
Opuntia maxima Mill.	Unresolved		WCSP (in review)
Opuntia maxima Salm-Dyck ex DC.	Unresolved		WCSP (in review)
Opuntia maxonii J.G. Ortega	Synonym		TRO
Opuntia megacantha Salm-Dyck	Accepted		TRO
Opuntia megacarpa Griffiths	Synonym		TRO
Opuntia megalantha Griffiths	Unresolved		WCSP (in review)
Opuntia megalanthra Rose	Unresolved		WCSP (in review)
Opuntia megalarthra Rose	Unresolved		WCSP (in review)
Opuntia megapotamica Arechav.	Accepted		TRO
Opuntia megarhiza Rose	Accepted		TRO
Opuntia megarhiza subsp. pachyrrhiza (H.M. Hern., Gomez-Hin. & Barcenas) U. Guzmán & Mandujano	Accepted		TRO
Opuntia megasperma Howell	Accepted		TRO
Opuntia megliolii (R.Kiesling) Kiessling	Unresolved		WCSP (in review)
Opuntia melanosperma Svenson	Synonym		TRO
Opuntia mesacantha Raf.	Synonym		TRO
Opuntia mesacantha var. cymochila (Engelm. & J.M. Bigelow) J.M. Coult.	Synonym		TRO
Opuntia mesacantha var. grandiflora (Engelm.) J.M. Coult.	Unresolved		TRO
Opuntia mesacantha var. macrorhiza (Engelm.) J.M. Coult.	Synonym		TRO
Opuntia mesacantha var. microsperma (Engelm. & J.M. Bigelow) J.M. Coult.	Unresolved		TRO
Opuntia mesacantha var. oplocarpa J.M. Coult.	Synonym		TRO
Opuntia mesacantha var. stenochila (Engelm. & J.M. Bigelow) J.M. Coult.	Synonym		TRO
Opuntia mesacantha var. vaseyi J.M. Coult.	Synonym		TRO
Opuntia metternichii Salm-Dyck	Unresolved		WCSP (in review)
Opuntia metuenda Pittier	Unresolved		WCSP (in review)
Opuntia mexicana Pfeiff.	Unresolved		WCSP (in review)
Opuntia micrarthra Griffiths	Unresolved		WCSP (in review)
Opuntia microcarpa K. Schum.	Synonym		TRO
Opuntia microdasys (Lehm.) Pfeiff.	Accepted		TRO
Opuntia microdasys var. albispina Fobe	Synonym		TRO
Opuntia microdasys var. laevior Salm-Dyck	Synonym		TRO
Opuntia microdasys subsp. microdasys	Accepted		TRO
Opuntia microdasys var. minor Salm-Dyck	Synonym		TRO
Opuntia microdasys var. pallida Borg	Synonym		TRO
Opuntia microdasys var. rufida (Engelm.) K. Schum.	Synonym		TRO
Opuntia microdasys subsp. rufida (Engelm.) U. Guzmán & Mandujano	Accepted		TRO
Opuntia microdisca F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia microthele Pfeiff.	Unresolved		WCSP (in review)
Opuntia mieckleyi K.Schum.	Unresolved		WCSP (in review)
Opuntia militaris Britton & Rose	Synonym		TRO
Opuntia millspaughii Britton	Unresolved		WCSP (in review)
Opuntia mininuta (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia minor Müll. Hal.	Unresolved		TRO
Opuntia minuscula (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia minuta (Backeb.) A. Cast.	Synonym		TRO
Opuntia miquelii Monv.	Synonym		TRO
Opuntia mira (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia missouriensis DC.	Synonym		TRO
Opuntia missouriensis var. albispina Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia missouriensis var. platycarpa Engelm.	Synonym		TRO
Opuntia missouriensis var. rufispina Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia missouriensis var. trichophora Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia mistiensis (Backeb.) G.D. Rowley	Accepted		TRO
Opuntia moelleri A. Berger	Synonym		TRO
Opuntia mohavensis Engelm. & J.M.Bigelow	Unresolved		WCSP (in review)
Opuntia mojavensis Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia molesta Brandegee	Synonym		WCSP (in review)
Opuntia molfinoi (Speg.) Werderm.	Synonym		TRO
Opuntia molinensis Speg.	Synonym		TRO
Opuntia monacantha Haw.	Accepted		WCSP (in review)
Opuntia monacantha subsp. brunneogemmia (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia moniliformis (L.) Haw. ex Steud.	Synonym		TRO
Opuntia moniliformis f. guantanamana (Areces) Govaerts	Synonym		TRO
Opuntia montana Sencke ex Haage	Unresolved		WCSP (in review)
Opuntia montevideensis Speg.	Unresolved		WCSP (in review)
Opuntia monticola Phil.	Unresolved		WCSP (in review)
Opuntia morenoi K.Schum.	Unresolved		WCSP (in review)
Opuntia mortolensis Britton & Rose	Unresolved		WCSP (in review)
Opuntia mucheri Starm.	Unresolved		WCSP (in review)
Opuntia muelleriana (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia multiareolata Backeb.	Unresolved		WCSP (in review)
Opuntia multigeniculata Clokey	Synonym		TRO
Opuntia munzii C.B.Wolf	Synonym		WCSP (in review)
Opuntia myriacantha F.A.C. Weber	Synonym		TRO
Opuntia nana Vis.	Synonym		TRO
Opuntia nashii Britton	Unresolved		WCSP (in review)
Opuntia nashii subsp. gibarensis (Areces) Govaerts	Synonym		TRO
Opuntia nejapensis Bravo	Accepted		TRO
Opuntia nelsonii Rose	Synonym		TRO
Opuntia nemoralis Griffiths	Unresolved		WCSP (in review)
Opuntia × neoarbuscula Griffiths	Synonym		WCSP (in review)
Opuntia neoargentina (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia neochrysacantha Bravo	Accepted		TRO
Opuntia neorutila Y.Itô	Unresolved		WCSP (in review)
Opuntia neuquensis Borg	Synonym		TRO
Opuntia nicholii L.D. Benson	Synonym		TRO
Opuntia nigricans (Haw.) Haw.	Synonym		TRO
Opuntia nigrispina K. Schum.	Synonym		TRO
Opuntia nigrita Griffiths	Synonym		TRO
Opuntia nitens Small	Unresolved		WCSP (in review)
Opuntia noodtiae (Backeb. & H. Jacobsen) G.D. Rowley	Synonym		TRO
Opuntia nopalilla Karw. ex Salm-Dyck	Unresolved		WCSP (in review)
Opuntia nuda (Backeb.) G.D. Rowley	Accepted		TRO
Opuntia obliqua Backeb.	Unresolved		WCSP (in review)
Opuntia oblongata H. Wendl.	Synonym		TRO
Opuntia obovata Griffiths	Unresolved		WCSP (in review)
Opuntia × occidentalis Engelm. & J. M. Bigelow (pro sp.)	Synonym		TRO
Opuntia occidentalis var. covillei (Britton & Rose) Parish	Unresolved		TRO
Opuntia occidentalis var. littoralis (Engelm.) Parish ex Jeps.	Synonym		TRO
Opuntia occidentalis var. megacarpa (Griffiths) Munz	Unresolved		TRO
Opuntia occidentalis var. piercei (Fosberg) Munz	Synonym		TRO
Opuntia occidentalis var. vaseyi (J.M. Coult.) Munz	Synonym		TRO
Opuntia ochrocentra Small ex Britton & Rose	Synonym		TRO
Opuntia oligacantha Pfeiff.	Unresolved		WCSP (in review)
Opuntia olmeca Pérez Crisanto, J.Reyes & F.Brachet	Unresolved		WCSP (in review)
Opuntia oplocarpa Engelm. ex J.M. Coult.	Unresolved		TRO
Opuntia opuntia (L.) H. Karst.	Synonym		TRO
Opuntia opuntia (L.) J.M. Coult.	Accepted		TRO
Opuntia orbiculata Salm-Dyck ex Pfeiff.	Accepted		TRO
Opuntia oricola Philbrick	Accepted		TRO
Opuntia orurensis Cárdenas	Synonym		TRO
Opuntia ottonis G.Don	Unresolved		WCSP (in review)
Opuntia ovallei Gay	Synonym		TRO
Opuntia ovata Pfeiff.	Synonym		TRO
Opuntia ovoides Lem.	Unresolved		WCSP (in review)
Opuntia pachona Griffiths	Synonym		TRO
Opuntia pachypus K. Schum.	Accepted		TRO
Opuntia pachyrrhiza H.M. Hern., Gomez-Hin. & Barcenas	Synonym		TRO
Opuntia paediophila A. Cast.	Synonym		TRO
Opuntia pailana Weing.	Accepted		TRO
Opuntia pallida Rose	Synonym		TRO
Opuntia palmadora Britton & Rose	Synonym		WCSP (in review)
Opuntia palmadora subsp. catingicola (Werderm.) P.J. Braun & Esteves	Unresolved		TRO
Opuntia palmeri Engelm. ex J.M. Coult.	Synonym		TRO
Opuntia pampeana Speg.	Synonym		TRO
Opuntia panellana (Backeb.) Backeb.	Unresolved		WCSP (in review)
Opuntia papyracantha Phil.	Unresolved		WCSP (in review)
Opuntia papyracantha K.Schum.	Unresolved		WCSP (in review)
Opuntia paraguayensis K. Schum.	Accepted		TRO
Opuntia parishii Orcutt	Synonym		TRO
Opuntia parkeri J.M. Coult.	Synonym		TRO
Opuntia parmentieri Pfeiff.	Unresolved		WCSP (in review)
Opuntia parryi Engelm.	Synonym		TRO
Opuntia parryi var. serpentina (Engelm.) L.D. Benson	Synonym		TRO
Opuntia parva A.Berger	Unresolved		WCSP (in review)
Opuntia parviclada S. Arias & see Gama Lopez, Susana	Accepted		TRO
Opuntia parvispina Salm-Dyck	Unresolved		WCSP (in review)
Opuntia parvula Salm-Dyck	Unresolved		WCSP (in review)
Opuntia pascoensis Britton & Rose	Synonym		TRO
Opuntia patagonica Phil.	Synonym		WCSP (in review)
Opuntia peckii J.A.Purpus	Unresolved		WCSP (in review)
Opuntia pelaguensis Salm-Dyck	Unresolved		WCSP (in review)
Opuntia penicilligera Speg.	Accepted		TRO
Opuntia pennellii Britton & Rose	Unresolved		WCSP (in review)
Opuntia pentlandii Salm-Dyck	Synonym		TRO
Opuntia perrita Griffiths	Synonym		TRO
Opuntia pes-corvi Leconte ex Chapm.	Unresolved		WCSP (in review)
Opuntia pestifer Britton & Rose	Synonym		TRO
Opuntia phaeacantha Engelm.	Accepted		TRO
Opuntia phaeacantha var. brunnea Engelm.	Synonym		TRO
Opuntia phaeacantha subsp. camanchica (Engelm. & J.M. Bigelow) Borg	Synonym		TRO
Opuntia phaeacantha var. camanchica (Engelm. & J.M. Bigelow) L.D. Benson	Accepted		TRO
Opuntia phaeacantha var. chihuahuensis (Rose) Bravo	Synonym		TRO
Opuntia phaeacantha var. discata (Griffiths) L.D. Benson & Walk.	Synonym		TRO
Opuntia phaeacantha var. flavispina L.D. Benson	Synonym		TRO
Opuntia phaeacantha var. laevis (J.M. Coult.) L.D. Benson	Synonym		TRO
Opuntia phaeacantha var. major Engelm.	Synonym		TRO
Opuntia phaeacantha var. nigricans Engelm.	Synonym		TRO
Opuntia phaeacantha var. piercei Fosberg	Synonym		TRO
Opuntia phaeacantha var. spinosibacca (M.S. Anthony) L.D. Benson	Synonym		TRO
Opuntia phaeacantha var. wootonii (Griffiths) L.D. Benson	Accepted		TRO
Opuntia philippii F.Haage & M.Schmidt ex Bois	Unresolved		WCSP (in review)
Opuntia phyllacantha Salm-Dyck ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia phyllanthus (L.) Mill.	Synonym		TRO
Opuntia picardae Urb.	Unresolved		WCSP (in review)
Opuntia picardoi Marn.-Lap.	Unresolved		WCSP (in review)
Opuntia piccolomini auct.	Unresolved		WCSP (in review)
Opuntia pilifera F.A.C. Weber	Accepted		TRO
Opuntia pinkavae B.D.Parfitt	Unresolved		WCSP (in review)
Opuntia pisciformis Small ex Britton & Rose	Unresolved		WCSP (in review)
Opuntia pititache (Karw. ex Pfeiff.) F.A.C. Weber	Synonym		TRO
Opuntia pittieri Britton & Rose	Unresolved		WCSP (in review)
Opuntia pituitosa (F. Ritter) Iliff	Accepted		TRO
Opuntia platyacantha Salm-Dyck	Synonym		TRO
Opuntia platynoda Griffiths	Unresolved		WCSP (in review)
Opuntia plumbea Rose	Accepted		TRO
Opuntia poecilacantha Backeb.	Synonym		TRO
Opuntia poeppigii Otto ex Pfeiff.	Synonym		WCSP (in review)
Opuntia pollardii Britton & Rose	Unresolved		WCSP (in review)
Opuntia polyacantha Haw.	Accepted		TRO
Opuntia polyacantha var. albispina (Engelm. & J.M. Bigelow) J.M. Coult.	Accepted		TRO
Opuntia polyacantha var. arenaria (Engelm.) B.D. Parfitt	Synonym		TRO
Opuntia polyacantha var. erinacea (Engelm. & J.M. Bigelow) B.D. Parfitt	Synonym		TRO
Opuntia polyacantha var. hystericina (Engelm. & J.M. Bigelow) B.D. Parfitt	Accepted		TRO
Opuntia polyacantha var. juniperina (Britton & Rose) L.D. Benson	Synonym		TRO
Opuntia polyacantha var. nicholii (L.D. Benson) B.D. Parfitt	Accepted		TRO
Opuntia polyacantha var. platycarpa (Engelm.) J.M. Coult.	Accepted		TRO
Opuntia polyacantha var. polyacantha	Accepted		TRO
Opuntia polyacantha var. rufispina (Engelm. & J.M. Bigelow) L.D. Benson	Synonym		TRO
Opuntia polyacantha var. schweriniana (K. Schum.) Backeb.	Accepted		TRO
Opuntia polyacantha var. trichophora (Engelm. & J.M. Bigelow) J.M. Coult.	Synonym		TRO
Opuntia polyantha Haw.	Unresolved		WCSP (in review)
Opuntia polycarpa Small	Unresolved		WCSP (in review)
Opuntia polymorpha Pfeiff.	Unresolved		WCSP (in review)
Opuntia porteri Brandegee ex F.A.C.Weber	Synonym		WCSP (in review)
Opuntia posnanskyana Cárdenas	Synonym		TRO
Opuntia pottsii Salm-Dyck	Synonym		TRO
Opuntia praecox J.Forbes	Unresolved		WCSP (in review)
Opuntia prasina Speg.	Unresolved		WCSP (in review)
Opuntia prate Sabine ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia procumbens Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia prolifera Engelm.	Synonym		WCSP (in review)
Opuntia prostrata Monv. & Lem. ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia protracta Lem. ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia pruinosa Salm-Dyck	Unresolved		WCSP (in review)
Opuntia pseudo-udonis (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia pseudotuna Salm-Dyck	Unresolved		WCSP (in review)
Opuntia puberula Pfeiff.	Synonym		TRO
Opuntia pubescens H.L.Wendl. ex Pfeiff.	Accepted		WCSP (in review)
Opuntia puelchana A. Cast.	Synonym		TRO
Opuntia pulchella Engelm.	Synonym		TRO
Opuntia pulverulenta Pfeiff.	Unresolved		WCSP (in review)
Opuntia pulvinata DC.	Unresolved		WCSP (in review)
Opuntia pumila Rose	Accepted		TRO
Opuntia punta-caillan (Rauh & Backeb.) G.D. Rowley	Accepted		TRO
Opuntia purpurea R.E. Fr.	Synonym		TRO
Opuntia pusilla (Haw.) Haw.	Synonym		TRO
Opuntia pycnantha Engelm.	Accepted		TRO
Opuntia pycnantha var. margaritana J.M. Coult.	Synonym		TRO
Opuntia pygmaea (Wiegand & Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia pyriformis Rose	Accepted		TRO
Opuntia pyrocarpa Griffiths	Unresolved		WCSP (in review)
Opuntia pyrrhacantha K. Schum.	Accepted		TRO
Opuntia pyrrhantha (F. Ritter) P.J. Braun & Esteves	Synonym		TRO
Opuntia quimilo K. Schum.	Accepted		TRO
Opuntia quipa F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia quitensis F.A.C. Weber	Accepted		TRO
Opuntia rafinesquei Engelm.	Synonym		TRO
Opuntia rafinesquei f. arkansana (Engelm. ex Rumpler) Schelle	Unresolved		TRO
Opuntia rafinesquei var. arkansana Engelm. ex Rumpler	Synonym		TRO
Opuntia rafinesquei f. cymochila (Engelm. & J.M. Bigelow) Schelle	Synonym		TRO
Opuntia rafinesquei var. microsperma Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia rafinesquei var. minor Engelm.	Synonym		TRO
Opuntia rafinesquei f. oplocarpa (J.M. Coult.) Schelle	Unresolved		TRO
Opuntia rafinesquei var. vaseyi (J.M. Coult.) K. Schum.	Synonym		TRO
Opuntia rahmeri Phil.	Unresolved		WCSP (in review)
Opuntia ramosissima Engelm.	Synonym		WCSP (in review)
Opuntia ramulifera Salm-Dyck	Synonym		TRO
Opuntia rarissima (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia rastrera F.A.C. Weber	Accepted		TRO
Opuntia rauhii (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia rauppiana K. Schum.	Synonym		TRO
Opuntia recondita Griffiths	Synonym		TRO
Opuntia recurvospina Griffiths	Unresolved		WCSP (in review)
Opuntia reflexa Mackensen	Unresolved		WCSP (in review)
Opuntia reflexispina Wiggins & Rollins	Synonym		TRO
Opuntia reicheana Espinosa	Unresolved		WCSP (in review)
Opuntia repens Karw. ex Salm-Dyck	Unresolved		WCSP (in review)
Opuntia repens Bello	Unresolved		WCSP (in review)
Opuntia reptans Karw. ex W.H.Baxter	Unresolved		WCSP (in review)
Opuntia retrorsa Speg.	Synonym		TRO
Opuntia retrospinosa Lem.	Unresolved		WCSP (in review)
Opuntia rhodantha K. Schum.	Synonym		TRO
Opuntia rhodantha var. xanthostemma (K. Schum.) Rehder	Synonym		TRO
Opuntia rileyi J.G. Ortega	Accepted		TRO
Opuntia riojana Hosseus	Unresolved		TRO
Opuntia riparia Griffiths	Unresolved		WCSP (in review)
Opuntia ritteri A. Berger	Accepted		TRO
Opuntia riviereana Backeb.	Accepted		TRO
Opuntia robinsonii J.G. Ortega	Accepted		TRO
Opuntia roborensis Cárdenas	Synonym		TRO
Opuntia robusta J.C. Wendl.	Accepted		TRO
Opuntia robusta var. guerrana (Griffiths) Sánchez-Mej.	Synonym		TRO
Opuntia robusta var. larreyi (F.A.C. Weber ex Coult.) Bravo	Synonym		TRO
Opuntia × rooneyi M.P.Griff.	Unresolved		WCSP (in review)
Opuntia rosarica G.E. Linds.	Synonym		TRO
Opuntia rosea DC.	Synonym		WCSP (in review)
Opuntia rosea (hort. ex A. Dietr.) K. Schum.	Accepted		TRO
Opuntia roseana Mackensen	Unresolved		WCSP (in review)
Opuntia rosiflora K.Schum.	Unresolved		WCSP (in review)
Opuntia rossiana (Heinrich & Backeb.) D.R. Hunt	Synonym		TRO
Opuntia rotundifolia Brandegee	Synonym		TRO
Opuntia roxburghiana Voigt	Unresolved		WCSP (in review)
Opuntia rubescens Salm-Dyck ex DC.	Unresolved		WCSP (in review)
Opuntia rubiflora Davidson	Unresolved		WCSP (in review)
Opuntia rubiflora Griffiths	Unresolved		WCSP (in review)
Opuntia rubrifolia Engelm. ex J.M.Coult.	Unresolved		WCSP (in review)
Opuntia rufida Engelm.	Synonym		TRO
Opuntia rufida var. tortiflora M.S. Anthony	Synonym		TRO
Opuntia rugosa Griffiths	Unresolved		WCSP (in review)
Opuntia ruiz-lealii A. Cast.	Synonym		TRO
Opuntia russellii Britton & Rose	Synonym		TRO
Opuntia ruthei A.Berger	Unresolved		WCSP (in review)
Opuntia rutila Nutt.	Unresolved		WCSP (in review)
Opuntia rzedowskii Scheinvar	Synonym		TRO
Opuntia sabinii Pfeiff.	Unresolved		WCSP (in review)
Opuntia salagria A. Cast.	Synonym		TRO
Opuntia salicornoides Spreng. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia salmiana Parm. ex Pfeiff.	Accepted		TRO
Opuntia salmii J.Forbes	Unresolved		WCSP (in review)
Opuntia salvadorensis Britton & Rose	Unresolved		WCSP (in review)
Opuntia sanctae-barbarae D.R.Hunt	Unresolved		WCSP (in review)
Opuntia sanfelipensis Rebman	Synonym		WCSP (in review)
Opuntia sanguinea Proctor	Unresolved		WCSP (in review)
Opuntia sanguinocula Griffiths	Unresolved		WCSP (in review)
Opuntia santamaria (E.M.Baxter) Wiggins	Synonym		WCSP (in review)
Opuntia santamaria (Baxter) Bravo	Synonym		TRO
Opuntia santarita (Griffiths & Hare) Rose	Accepted		TRO
Opuntia saxatilis (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia saxicola Howell	Accepted		TRO
Opuntia scheeri F.A.C. Weber	Accepted		TRO
Opuntia schickendantzii F.A.C. Weber	Accepted		TRO
Opuntia schomburgkii Salm-Dyck	Unresolved		WCSP (in review)
Opuntia schottii Engelm.	Synonym		TRO
Opuntia schottii var. grahamii (Engelm.) L.D. Benson	Synonym		TRO
Opuntia schulzii A. Cast. & Lelong	Synonym		TRO
Opuntia schumannii F.A.C.Weber ex A.Berger	Accepted		WCSP (in review)
Opuntia schumannii Speg.	Synonym		TRO
Opuntia schweriniana K. Schum.	Synonym		TRO
Opuntia securigera Borg	Unresolved		WCSP (in review)
Opuntia segethii F. Phil.	Synonym		TRO
Opuntia seguina C.Z.Nelson	Unresolved		WCSP (in review)
Opuntia semispinosa Griffiths	Synonym		TRO
Opuntia senilis Roezl	Unresolved		WCSP (in review)
Opuntia senilis Parm. ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia sericea G.Don ex Salm-Dyck	Unresolved		WCSP (in review)
Opuntia serpentina Engelm.	Synonym		TRO
Opuntia setigera (Backeb.) W.T.Marshall	Unresolved		WCSP (in review)
Opuntia setispina Engelm. ex Salm-Dyck, L.	Synonym		TRO
Opuntia shaferi Britton & Rose	Synonym		TRO
Opuntia shreveana A. Nelson	Synonym		TRO
Opuntia silvestris Backeb.	Unresolved		WCSP (in review)
Opuntia sinclairii Griffiths	Unresolved		WCSP (in review)
Opuntia skottsbergii Britton & Rose	Synonym		TRO
Opuntia soederstromiana Britton & Rose	Accepted		TRO
Opuntia soehrensii Britton & Rose	Synonym		TRO
Opuntia spathulata (Otto ex Pfeiff.) F.A.C. Weber	Synonym		TRO
Opuntia speciosa Steud.	Unresolved		WCSP (in review)
Opuntia spectatissima (Daston) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia spegazzinii F.A.C. Weber	Synonym		TRO
Opuntia sphaerica Foerster	Synonym		TRO
Opuntia sphaerica var. rauppiana (K. Schum.) G.D. Rowley	Synonym		TRO
Opuntia sphaerica var. unguispina (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia sphaerocarpa Engelm. & J.M.Bigelow	Unresolved		WCSP (in review)
Opuntia sphaerocarpa var. utahensis Engelm.	Synonym		TRO
Opuntia spinalba Raf.	Unresolved		WCSP (in review)
Opuntia spinaurea Karw. ex Salm-Dyck	Unresolved		WCSP (in review)
Opuntia spiniflora Phil.	Synonym		TRO
Opuntia × spinosibacca M. S. Anthony (pro sp.)	Accepted		TRO
Opuntia spinosior (Engelm.) Toumey	Synonym		TRO
Opuntia spinosior var. neomexicana Toumey	Synonym		TRO
Opuntia spinosissima Mill.	Unresolved		WCSP (in review)
Opuntia spinotecta Griffiths	Unresolved		WCSP (in review)
Opuntia spinulifera Salm-Dyck	Accepted		TRO
Opuntia spinulosa Salm-Dyck	Unresolved		WCSP (in review)
Opuntia spirocentra Engelm. & J.M.Bigelow ex Haage	Unresolved		WCSP (in review)
Opuntia splendens Pfeiff.	Unresolved		WCSP (in review)
Opuntia spraguei J.G. Ortega	Accepted		TRO
Opuntia squarrosa Griffiths	Unresolved		WCSP (in review)
Opuntia staffordae Bullock	Accepted		TRO
Opuntia stanlyi Engelm. ex B.D. Jacks.	Synonym		TRO
Opuntia stanlyi var. kunzei (Rose) L.D. Benson	Synonym		TRO
Opuntia stanlyi var. parishii (Orcutt) L.D. Benson	Synonym		TRO
Opuntia stanlyi var. peeblesiana L.D. Benson	Synonym		TRO
Opuntia stanlyi var. wrightiana (E.M. Baxter) L.D. Benson	Synonym		TRO
Opuntia stapeliae DC.	Unresolved		WCSP (in review)
Opuntia steiniana (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia stellata Salm-Dyck	Synonym		TRO
Opuntia stenarthra K.Schum.	Unresolved		WCSP (in review)
Opuntia stenochila Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia stenopetala Engelm.	Accepted		TRO
Opuntia stipata (Coult.) K.Schum.	Unresolved		WCSP (in review)
Opuntia straminea Sencke ex Haage	Unresolved		WCSP (in review)
Opuntia streptacantha Lem.	Accepted		TRO
Opuntia stricta (Haw.) Haw.	Accepted		WCSP (in review)
Opuntia stricta var. dillenii (Ker Gawl.) L.D. Benson	Synonym		TRO
Opuntia strigil Engelm.	Accepted		TRO
Opuntia strigil var. flexospina (Griffiths) L.D. Benson	Synonym		TRO
Opuntia strobiliformis A.Berger	Unresolved		WCSP (in review)
Opuntia subarmata Griffiths	Synonym		TRO
Opuntia subferox Schott ex Pfeiff.	Unresolved		WCSP (in review)
Opuntia subinermis Backeb.	Synonym		TRO
Opuntia subsphaerocarpa Speg.	Unresolved		WCSP (in review)
Opuntia subterranea R.E. Fr.	Synonym		TRO
Opuntia subulata (Muehlenpf.) Engelm.	Synonym		WCSP (in review)
Opuntia sulphurea G. Don	Accepted		TRO
Opuntia sulphurea Gillies ex Salm-Dyck	Unresolved		TRO
Opuntia sulphurea subsp. spinibarbis (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia superbospina Griffiths	Synonym		TRO
Opuntia syringacantha Pfeiff. ex C.F.Först.	Unresolved		WCSP (in review)
Opuntia tapona Engelm. ex J.M. Coult.	Accepted		TRO
Opuntia tarapacana Phil.	Synonym		TRO
Opuntia tardospina Griffiths	Synonym		TRO
Opuntia tayapayensis Cárdenas	Synonym		TRO
Opuntia taylorii Britton & Rose	Unresolved		WCSP (in review)
Opuntia tehuacana S. Arias & see Guzman Cruz, Leonardo Ulises	Accepted		TRO
Opuntia tehuantepecana (Bravo) Bravo	Accepted		TRO
Opuntia tenuiflora Small	Unresolved		WCSP (in review)
Opuntia tenuispina Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia tephrocactoides (Rauh & Backeb.) G.D. Rowley	Synonym		TRO
Opuntia teres F. Cels ex F.A.C. Weber	Synonym		TRO
Opuntia tesajo Engelm.	Synonym		WCSP (in review)
Opuntia tessellata Engelm.	Synonym		TRO
Opuntia tessellata var. cristata K. Schum.	Synonym		TRO
Opuntia testudinis-crus F.A.C. Weber	Synonym		TRO
Opuntia × tetracantha Toumey	Synonym		WCSP (in review)
Opuntia texana Griffiths	Synonym		TRO
Opuntia thornberi Thornber & Bonker	Synonym		TRO
Opuntia thurberi Engelm.	Synonym		WCSP (in review)
Opuntia thurberi var. alamosenis (Britton & Rose) Bravo	Synonym		TRO
Opuntia thurberi subsp. versicolor (Engelm. ex J.M. Coult.) Felger	Synonym		TRO
Opuntia ticnamarensis (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia tidbaldi Bigelow	Unresolved		TRO
Opuntia tidballii J.M.Bigelow	Unresolved		WCSP (in review)
Opuntia tilcarensis Backeb.	Unresolved		WCSP (in review)
Opuntia tomentella A. Berger	Synonym		TRO
Opuntia tomentosa Salm-Dyck	Accepted		TRO
Opuntia tomentosa var. hernandezii (DC.) Bravo	Synonym		TRO
Opuntia tortispina Engelm. & J.M. Bigelow	Synonym		TRO
Opuntia tortispina var. cymochila (Engelm. & J.M. Bigelow) Backeb.	Synonym		TRO
Opuntia toumeyi Rose	Unresolved		WCSP (in review)
Opuntia tracyi Britton	Synonym		TRO
Opuntia treleasei J.M. Coult.	Synonym		TRO
Opuntia triacantha (Willd.) Sweet	Accepted		TRO
Opuntia tribuloides Griffiths	Unresolved		WCSP (in review)
Opuntia trichophora (Engelm. & J.M. Bigelow) Britton & Rose	Synonym		TRO
Opuntia tricolor Griffiths	Synonym		TRO
Opuntia tuberculata Haw.	Unresolved		WCSP (in review)
Opuntia tuberculosirhopalica (Wiegand & Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia tuberiformis Phil.	Unresolved		WCSP (in review)
Opuntia tuberosa Pfeiff.	Synonym		TRO
Opuntia tumida (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia tuna (L.) Mill.	Accepted		TRO
Opuntia tuna-blanca Speg.	Unresolved		WCSP (in review)
Opuntia tunicata (Lehm.) Pfeiff.	Synonym		WCSP (in review)
Opuntia tunicata var. davisii (Engelm. & J.M. Bigelow) L.D. Benson	Synonym		TRO
Opuntia tunoidea Gibbes	Unresolved		WCSP (in review)
Opuntia tunoides Britton & Shafer ex Bold.	Unresolved		TRO
Opuntia turbinata Small	Unresolved		WCSP (in review)
Opuntia turgida Small ex Britton & Rose	Unresolved		WCSP (in review)
Opuntia turpinii Lem.	Unresolved		WCSP (in review)
Opuntia udonis Weing.	Synonym		TRO
Opuntia ula Engelm. x O. kelvinensis	Unresolved		TRO
Opuntia umbrella Steud.	Unresolved		WCSP (in review)
Opuntia undulata Griffiths	Accepted		TRO
Opuntia unguispina Backeb.	Accepted		TRO
Opuntia urbaniana Werderm.	Unresolved		WCSP (in review)
Opuntia ursina F.A.C. Weber	Synonym		TRO
Opuntia utahensis J.A.Purpus	Unresolved		WCSP (in review)
Opuntia utkilio Speg.	Synonym		TRO
Opuntia vaginata Engelm.	Synonym		TRO
Opuntia valentinii (Speg.) Kiessling	Unresolved		WCSP (in review)
Opuntia valida Griffiths	Unresolved		WCSP (in review)
Opuntia × vaseyi (J.M. Coult.) Britton & Rose (pro sp.)	Accepted		TRO
Opuntia velutina F.A.C. Weber	Accepted		TRO
Opuntia velutina var. affinis (Griffiths) Bravo	Synonym		TRO
Opuntia velutina var. macdougaliana (Rose) Bravo	Synonym		TRO
Opuntia verschaeffeltii F. Cels ex F.A.C. Weber	Synonym		TRO
Opuntia versicolor Engelm. ex Toumey	Synonym		WCSP (in review)
Opuntia versicolor Engelm. ex J.M. Coult.	Synonym		TRO
Opuntia verticosa Weing.	Synonym		TRO
Opuntia vestita Salm-Dyck	Synonym		TRO
Opuntia vexans Griffiths	Synonym		TRO
Opuntia vilis Rose	Synonym		TRO
Opuntia violacea Engelm.	Synonym		TRO
Opuntia violacea Engelm. ex B.D. Jacks.	Synonym		TRO
Opuntia violacea var. castetteri L.D. Benson	Synonym		TRO
Opuntia violacea var. gosseliniana (F.A.C. Weber) L.D. Benson	Synonym		TRO
Opuntia violacea var. macrocentra (Engelm.) L.D. Benson	Synonym		TRO
Opuntia violacea var. santarita (Griffiths & Hare) L.D. Benson	Synonym		TRO
Opuntia virens Ten.	Unresolved		WCSP (in review)
Opuntia virgata Pfeiff.	Unresolved		WCSP (in review)
Opuntia virgata C.F.Först.	Unresolved		WCSP (in review)
Opuntia × viridiflora Britton & Rose	Synonym		WCSP (in review)
Opuntia viridirubra (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia viridirubra subsp. rubrogemmia (F. Ritter) P.J. Braun & Esteves	Accepted		TRO
Opuntia vitelliniflora (F. Ritter) P.J. Braun & Esteves	Synonym		TRO
Opuntia × vivipara Rose	Synonym		WCSP (in review)
Opuntia vulgaris Mill.	Synonym		TRO
Opuntia vulgaris var. nana (Vis.) K. Schum.	Unresolved		TRO
Opuntia vulpina F.A.C. Weber	Synonym		TRO
Opuntia wagenknechtii (F. Ritter) D.R. Hunt	Synonym		TRO
Opuntia wagneri F.A.C.Weber	Unresolved		WCSP (in review)
Opuntia weberi Speg.	Unresolved		WCSP (in review)
Opuntia weingartiana Backeb.	Synonym		TRO
Opuntia wentiana Britton & Rose	Synonym		WCSP (in review)
Opuntia werneri Eggli	Unresolved		WCSP (in review)
Opuntia wetmorei Britton & Rose	Unresolved		WCSP (in review)
Opuntia whipplei Engelm. & J.M.Bigelow	Synonym		WCSP (in review)
Opuntia whipplei var. enodis Peebles	Synonym		TRO
Opuntia whipplei var. laevior Engelm.	Synonym		TRO
Opuntia whipplei var. multigeniculata (Clokey) L.D. Benson	Unresolved		TRO
Opuntia whipplei var. spinosior Engelm.	Synonym		WCSP (in review)
Opuntia whitneyana E.M. Baxter	Synonym		TRO
Opuntia wiegandii (Backeb.) G.D.Rowley	Unresolved		WCSP (in review)
Opuntia wigginsii L.D. Benson	Synonym		TRO
Opuntia wilcoxii Britton & Rose	Accepted		TRO
Opuntia wilkeana (Backeb.) G.D. Rowley	Synonym		TRO
Opuntia winteriana A.Berger	Unresolved		WCSP (in review)
Opuntia wolfei (L.D. Benson) M.A. Baker	Synonym		TRO
Opuntia woodsii Backeb.	Unresolved		WCSP (in review)
Opuntia wootonii Griffiths	Synonym		TRO
Opuntia wrightiana (E.M. Baxter) Peebles	Synonym		TRO
Opuntia wrightii Engelm.	Synonym		TRO
Opuntia xanthoglochia Griffiths	Unresolved		WCSP (in review)
Opuntia xanthostemma K. Schum.	Synonym		TRO
Opuntia xerocarpa Griffiths	Unresolved		WCSP (in review)
Opuntia yanganucensis (Rauh & Backeb.) G.D. Rowley	Accepted		TRO
Opuntia youngii C.Z.Nelson	Unresolved		WCSP (in review)
Opuntia zacana Howell	Synonym		TRO
Opuntia zacuapanensis A.Berger	Unresolved		WCSP (in review)
Opuntia zamudioi Scheinvar	Accepted		TRO
Opuntia zebrina Small	Unresolved		WCSP (in review)
Opuntia zehnderi (Rauh & Backeb.) G.D. Rowley	Accepted		TRO
Opuntia zuniensis Griffiths	Synonym		TRO