- All About Opuntia Rubrifolia Engelm. Ex Coult.
- All About Opuntia Rutila Nutt.
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm.
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Erinacea Engelm. & Bigelow Ex Engelm. [superfluous Autonym]
- All About Grizzlybear Pricklypear (Opuntia Polyacantha Haw. Var. Hystricina (Engelm. & Bigelow) Parfitt)
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Hystricina (Engelm. & Bigelow) L. Benson
- All About Opuntia Hystricina Engelm. & Bigelow
- All About Navajo Bridge Pricklypear
- All About Opuntia Nicholii L. Benson
- All About Hairspine Pricklypear
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Paucispina Dunkle
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Ursina (A. Weber) Parish
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Utahensis (Engelm.) L. Benson
- All About Opuntia Phaeacantha Engelm. Var. Brunnea (Engelm.) Engelm.
- All About Opuntia Phaeacantha Engelm. Var. Camanchica (Engelm. & Bigelow) L. Benson
- All About Opuntia Phaeacantha Engelm. Var. Major Engelm.
- All About Opuntia Phaeacantha Engelm. Var. Mojavensis (Engelm.) Fosberg
- All About Opuntia Phaeacantha Engelm. Var. Nigricans (Engelm.) Engelm.
- All About Opuntia Phaeacantha Engelm. Var. Phaeacantha Engelm. [superfluous Autonym]
- All About Opuntia Phaeacantha Engelm. Var. Superbospina (Griffiths) L. Benson
- All About Opuntia Superbospina Griffiths
- All About Opuntia Woodsii Backeberg
- All About Grizzlybear Pricklypear
- All About Opuntia ×occidentalis Engelm. & Bigelow (pro Sp.) [littoralis × (engelmannii × Phaeacantha)]
- All About Chaparral Pricklypear
- All About Tulip Pricklypear (Opuntia Phaeacantha Engelm.)
- All About Opuntia Arizonica Griffiths
- All About Opuntia Camanchica Engelm. & Bigelow
- All About Opuntia Canada Griffiths
- All About Opuntia Charlestonensis Clokey
- All About Opuntia Dulcis Engelm.
- All About Opuntia Engelmannii Salm-Dyck Ex Engelm. Var. Cycloides Engelm. & Bigelow
- All About Opuntia Gilvescens Griffiths
- All About Opuntia Mojavensis Engelm.
- All About Twistspine Pricklypear (Opuntia Macrorhiza Engelm. Var. Pottsii (Salm-Dyck) L. Benson)
- All About Opuntia Ballii Rose
- All About Opuntia Phaeacantha Engelm. Var. Tenuispina (Engelm. & Bigelow) Weniger
- All About Opuntia Pottsii Salm-Dyck
- All About Twistspine Pricklypear (Opuntia Macrorhiza Engelm.)
- All About Seashore Cactus
- All About Opuntia Littoralis (Engelm.) Cockerell Var. Martiniana (L. Benson) L. Benson
- All About Opuntia Macrocentra Engelm. Var. Martiniana L. Benson
- All About Angel's-wings
- All About Common Pricklypear
- All About Opuntia Vulgaris Auct. Non P. Mill. [misapplied]
- All About Opuntia Compressa J.F. Macbr. Var. Grandiflora (Engelm.) Weniger
- All About Opuntia Compressa J.F. Macbr. Var. Macrorhiza (Engelm.) L. Benson
- All About Opuntia Compressa J.F. Macbr. Var. Stenochila (Engelm.) Weniger
- All About Opuntia Grandiflora Engelm.
- All About Opuntia Leptocarpa MacKensen
- All About Opuntia Mackensenii Rose
- All About Opuntia Plumbea Rose
- All About Opuntia Sphaerocarpa Engelm. & Bigelow
- All About Opuntia Tenuispina Engelm. & Bigelow
- All About Opuntia Tortispina Engelm. & Bigelow
- All About Arborescent Pricklypear
- All About Coastal Pricklypear (Opuntia Littoralis (Engelm.) Cockerell Var. Littoralis)
- All About Opuntia Engelmannii Salm-Dyck Ex Engelm. Var. Littoralis Engelm.
- All About Opuntia Occidentalis Engelm. & Bigelow Var. Littoralis (Engelm.) Parish
- All About Coastal Pricklypear (Opuntia Littoralis (Engelm.) Cockerell)
- All About Purple Pricklypear
- All About Opuntia Violacea Engelm.
- All About Opuntia Violacea Engelm. Var. Castetteri L. Benson
- All About Opuntia Violacea Engelm. Var. Macrocentra (Engelm.) L. Benson
- All About Purple Pricklypear (Opuntia Macrocentra Engelm.)
- All About Twistspine Pricklypear
- All About Devil's-tongue (Opuntia Humifusa (Raf.) Raf.)
- All About Opuntia Calcicola Wherry
- All About Opuntia Compressa Auct. Non J.F. Macbr. [misapplied]
- All About Opuntia Compressa J.F. Macbr. Var. Allairei (Griffiths) Weniger
- All About Opuntia Compressa J.F. Macbr. Var. Fuscoatra (Engelm.) Weniger
- All About Opuntia Compressa J.F. Macbr. Var. Microsperma (Engelm. & Bigelow) L. Benson
- All About Opuntia Cumulicola Small
- All About Opuntia Humifusa (Raf.) Raf. Var. Humifusa (Raf.) Raf. [superfluous Autonym]
- All About Opuntia Rafinesquei Engelm.
- All About Tulip Pricklypear
- All About Opuntia Phaeacantha Engelm. Var. Laevis (Coult.) L. Benson
- All About Brittle Pricklypear
- All About Cactus Fragilis Nutt.
- All About Opuntia Brachyarthra Engelm. & Bigelow
- All About Opuntia Fragilis (Nutt.) Haw. Ssp. Brachyarthra (Engelm. & Bigelow) W.A. Weber
- All About Opuntia Fragilis (Nutt.) Haw. Var. Brachyarthra (Engelm. & Bigelow) Coult.
- All About Opuntia Fragilis (Nutt.) Haw. Var. Denudata Wieg. & Backeberg
- All About Opuntia Fragilis (Nutt.) Haw. Var. Fragilis (Nutt.) Haw. [superfluous Autonym]
- All About Violet Pricklypear
- All About Opuntia Chlorotica Engelm. & Bigelow Var. Gosseliniana (A. Weber) Ferguson
- All About Opuntia Violacea Engelm. Var. Gosseliniana (A. Weber) L. Benson
- All About Opuntia ×subarmata Griffiths (pro Sp.)
- All About Opuntia Tardospina Griffiths
- All About Opuntia Tricolor Griffiths
- All About Cactus Apple (Opuntia Engelmannii Salm-Dyck Ex Engelm. Var. Flavispina (L. Benson) Parfitt & Pinkava)
- All About Opuntia Phaeacantha Engelm. Var. Flavispina L. Benson
- All About Cactus Apple (Opuntia Engelmannii Salm-Dyck Ex Engelm.)
- All About Barbary Fig
- All About Cactus Ficus-indica L.
- All About Opuntia Compressa J.F. Macbr.
- All About Opuntia Opuntia (L.) Karst.
- All About Opuntia Vulgaris P. Mill.
- All About Opuntia Ochrocentra Small
- All About Searchlight Pricklypear
- All About Opuntia ×demissa Griffiths (pro Sp.) [ficus-indica × Sp.]
- All About Cactus Apple (Opuntia Engelmannii Salm-Dyck Ex Engelm. Var. Engelmannii)
- All About Opuntia Dillei Griffiths
- All About Opuntia Discata Griffiths
- All About Opuntia Lindheimeri Engelm. Var. Tricolor (Griffiths) L. Benson
- All About Opuntia Megacarpa Griffiths
- All About Opuntia Microcarpa Engelm. Ex B.D. Jackson
- All About Opuntia Occidentalis Engelm. & Bigelow Var. Megacarpa (Griffiths) Munz
- All About Opuntia Phaeacantha Engelm. Var. Discata (Griffiths) L. Benson & Walkington
- All About Beavertail Pricklypear (Opuntia Basilaris Engelm. & Bigelow)
- All About Dollarjoint Pricklypear
- All About Cochineal Nopal Cactus
- All About Cactus Cochenilliferus L.
- All About Nopalea Cochenillifera (L.) Salm-Dyck
- All About Grizzleybear Pricklypear
- All About Opuntia Columbiana Griffiths [hybrid]
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Columbiana (Griffiths) L. Benson
- All About Bullsuckers
- All About Opuntia Antillana Britt. & Rose
- All About Opuntia Basilaris Engelm. & Bigelow Var. Ramosa Parish
- All About Opuntia Basilaris Engelm. & Bigelow Var. Whitneyana (E.M. Baxter) E.M. Baxter Ex W.T. Marsh.
- All About Opuntia Brachyclada Griffiths Ssp. Humistrata (Griffiths) Wiggins & Wolf
- All About Opuntia Whitneyana E.M. Baxter
- All About Opuntia Whitneyana E.M. Baxter Var. Albiflora E.M. Baxter
- All About Beavertail Pricklypear (Opuntia Basilaris Engelm. & Bigelow Var. Brachyclada (Griffiths) Munz)
- All About Opuntia Brachyclada Griffiths
- All About Beavertail Pricklypear (Opuntia Basilaris Engelm. & Bigelow Var. Longiareolata (Clover & Jotter) L. Benson)
- All About Opuntia Longiareolata Clover & Jotter
- All About Trelease's Beavertail Pricklypear
- All About Opuntia Treleasei Coult.
- All About Golden Pricklypear
- All About Opuntia Basilaris Engelm. & Bigelow Var. Aurea (E.M. Baxter) W.T. Marsh.
- All About Opuntia Erinacea Engelm. & Bigelow Ex Engelm. Var. Aurea (E.M. Baxter) Welsh
- All About Devil's-tongue (Opuntia Austrina Small)
- All About Opuntia Compressa J.F. Macbr. Var. Austrina (Small) L. Benson
- All About Opuntia Eburnispina Small
- All About Opuntia Humifusa (Raf.) Raf. Var. Austrina (Small) Dress
- All About Opuntia Pollardii Britt. & Rose
- All About Opuntia Polycarpa Small
- All About Beavertail Pricklypear
- All About Opuntia Basilaris Engelm. & Bigelow Var. Heilii Welsh & Neese
- All About Oplismenus Hirtellus (L.) Beauv. Ssp. Setarius (Lam.) Mez Ex Ekman
- All About Oplismenus Compositus (L.) Beauv. Var. Setarius (Lam.) F.M. Bailey
- All About Oplismenus Setarius (Lam.) Roemer & J.A. Schultes
- All About Panicum Setarium Lam.
- All About Bristle Basketgrass (Oplismenus Hirtellus (L.) Beauv.)
- All About Oplopanax
- All About Devilsclub
- All About Echinopanax Horridus (Miq.) Dcne. & Planch. Ex H.A.T. Harms
- All About Fatsia Horrida (Smith) Benth. & Hook. F. Ex Brewer & S. Watson
- All About Pricklypear
- All About Southern Adderstongue
- All About Ophioglossum Pycnostichum (Fern.) A.& D. Löve
- All About Ophioglossum Vulgatum L. Var. Pycnostichum Fern.
- All About Ophiopogon
- All About Lilyturf (Ophiopogon Jaburan (Sieb.) Lodd.)
- All About Basketgrass
- All About Running Mountaingrass
- All About Panicum Compositum L.
- All About Bristle Basketgrass
- All About Oplismenus Burmanni Auct. Non (Retz.) Beauv. [misapplied]
- All About Panicum Hirtellum L.
- All About Ophioglossum Mononeuron E. St. John
- All About Ophioglossum Nudicaule L. F. Var. Minus Clausen
- All About Ophioglossum Nudicaule L. F. Var. Tenerum (Mett. Ex Prantl) Clausen
- All About Ophioglossum Tenerum Mett. Ex Prantl
- All About Longstem Adderstongue
- All About Large Adderstongue
- All About Northern Adderstongue
- All About Ophioglossum Vulgatum Auct. Non L. [misapplied]
- All About Ophioglossum Vulgatum L. Var. Alaskanum (E.G. Britt.) C. Christens.
- All About Ophioglossum Vulgatum L. Var. Pseudopodum (Blake) Farw.
- All About Adderstongue
- All About California Adderstongue
- All About Ophioglossum Lusitanicum L. Ssp. Californicum (Prantl) R.T. Clausen
- All About Ophioglossum Lusitanicum L. Var. Californicum (Prantl) Broun
- All About Bulbous Adderstongue
- All About Bulbous Adderstongue (Ophioglossum Crotalophoroides Walt.)
- All About Limestone Adderstongue
- All About Least Adderstongue
- All About Ophioglossum Dendroneuron E. St. John
- All About Ophioglossum Ellipticum Hook. & Grev.
- All About Onosmodium Molle Michx. Ssp. Subsetosum (Mackenzie & Bush) Cochrane
- All About Onosmodium Molle Michx. Var. Subsetosum (Mackenzie & Bush) Cronq.
- All About Onosmodium Subsetosum Mackenzie & Bush
- All About Soft-hair Marbleseed (Onosmodium Bejariense DC. Ex A. DC.)
- All About Wild Job's Tears
- All About Onosmodium Virginianum (L.) A. DC. Var. Hirsutum Mackenzie
- All About False Goldenweed
- All About Engelmann's False Goldenweed
- All About Haplopappus Engelmannii (Gray) Hall
- All About Leafy False Goldenweed (Oonopsis Foliosa (Gray) Greene)
- All About Lithospermum Carolinianum Auct. Non Lam. [misapplied]
- All About Onosmodium Hispidissimum Mackenzie
- All About Onosmodium Hispidissimum Mackenzie Var. Macrospermum Mackenzie & Bush
- All About Onosmodium Molle Michx. Ssp. Hispidissimum (Mackenzie) Boivin
- All About Onosmodium Molle Michx. Var. Hispidissimum (Mackenzie) Cronq.
- All About Western Marbleseed
- All About Onosmodium Molle Michx. Ssp. Occidentale (Mackenzie) Cochrane
- All About Onosmodium Molle Michx. Var. Occidentale (Mackenzie) I.M. Johnston
- All About Onosmodium Occidentale Mackenzie
- All About Onosmodium Occidentale Mackenzie Var. Sylvestre Mackenzie
- All About Softhair Marbleseed (Onosmodium Bejariense DC. Ex A. DC. Var. Subsetosum (Mackenzie & Bush) B.L. Turner)
- All About Scotch Cottonthistle
- All About Onopordum Acanthium L. Ssp. Acanthium L. [superfluous Autonym]
- All About Illyrian Cottonthistle
- All About Bull Cottonthistle
- All About Marbleseed
- All About Soft-hair Marbleseed
- All About Onosmodium Molle Michx.
- All About Onosmodium Molle Michx. Ssp. Bejariense (DC. Ex A. DC.) Cochrane
- All About Onosmodium Molle Michx. Ssp. Molle Michx. [superfluous Autonym]
- All About Onosmodium Molle Michx. Var. Bejariense (DC. Ex A. DC.) Cronq.
- All About Softhair Marbleseed
- All About Hedysarum Onobrychis L.
- All About Onobrychis Sativa Lam.
- All About Onobrychis Viciaefolia Scop. [orthographic Variant]
- All About Sensitive Fern
- All About Sensitive Fern (Onoclea Sensibilis L.)
- All About Restharrow
- All About Foxtail Restharrow
- All About Spiny Restharrow
- All About Ononis Campestris G. Koch & Ziz
- All About Cottonthistle
- All About Inflated Grasswidow
- All About Sisyrinchium Douglasii A. Dietr. Var. Inflatum (Suksdorf) P. Holmgren
- All About Sisyrinchium Inflatum (Suksdorf) St. John
- All About Douglas' Grasswidow (Olsynium Douglasii (A. Dietr.) Bickn.)
- All About Oncosiphon
- All About Stinknet
- All About Matricaria Globifera (Thunb.) Fenzl Ex Harv.
- All About Sainfoin
- All About Sainfoin (Onobrychis Viciifolia Scop.)
- All About Stiff Goldenrod (Oligoneuron Rigidum (L.) Small Var. Rigidum)
- All About Oligoneuron Grandiflorum (Raf.) Small
- All About Solidago Grandiflora Raf.
- All About Solidago Rigida L.
- All About Stiff Goldenrod (Oligoneuron Rigidum (L.) Small)
- All About Olneya
- All About Desert Ironwood
- All About Grasswidow
- All About Douglas' Grasswidow
- All About Sisyrinchium Douglasii A. Dietr.
- All About Sisyrinchium Inalatum A. Nels.
- All About Solidago Rigida L. Var. Glabrata E.L. Braun
- All About Solidago Rigida L. Var. Laevicaulis Shinners
- All About Stiff Goldenrod (Oligoneuron Rigidum (L.) Small Var. Humile (Porter) Nesom)
- All About Oligoneuron Canescens Rydb.
- All About Oligoneuron Corymbosum (Ell.) Small Var. Humile (Porter) Beaudry & Kapoor
- All About Solidago Canescens (Rydb.) Friesner