| Common Name | Scientific Name | Code |
| n/a | Beloglottis Schlechter | BELOG |
| n/a | Brachionidium distichophylla (Trin.) Stapf. [excluded] | BRDI17 |
| n/a | Brachionidium parvum Cogn. [excluded] | BRPA19 |
| n/a | Brassia gireoudiana Rchb. F. & Warsz. | BRGI3 |
| n/a | Brassia maculata R. Br. | BRMA15 |
| n/a | Calanthe hololeuca Reichenb. F. | CAHO25 |
| n/a | Calanthe R. Br. | CALAN3 |
| n/a | Calanthe triplicata Bateman | CATR31 |
| n/a | Cattleya gaskelliana Sander | CAGA10 |
| n/a | Cattleya labiata Lindl. [excluded] | CALA82 |
| n/a | Caularthron bicornutum (Hook.) Raf. [excluded] | CABI21 |
| n/a | Caularthron Raf. | CAULA2 |
| n/a | Corallorhiza maculata (Raf.) Raf. var. ozettensis E. Tisch | COMAO6 |
| n/a | Cranichis diphylla Sw. [excluded] | CRDI18 |
| n/a | Cypripedium ?alaskanum P.M. Brown [guttatum ? yatabeanum] | CYAL10 |
| n/a | Cypripedium ?andrewsii A.M. Fuller var. andrewsii | CYANA |
| n/a | Cypripedium ?andrewsii A.M. Fuller var. favillianum (J.T. Curtis) Boivin (pro nm.) | CYANF |
| n/a | Cypripedium ?andrewsii A.M. Fuller var. landonii (Gray) Boivin (pro nm.) | CYANL2 |
| n/a | Cypripedium ?andrewsii A.M. Fuller [candidum ? parviflorum] | CYAN2 |
| n/a | Cypripedium ?columbianum Sheviak [montanum ? parviflorum] | CYCO23 |
| n/a | Cyrtopodium andersonii (Lamb. ex Andr.) R. Br. ex Ait. f. [excluded] | CYAN13 |
| n/a | Dactylorhiza incarnata (L.) So? [excluded] | DAIN9 |
| n/a | Deiregyne Schlechter | DEIRE |
| n/a | Dendrobium bigibbum Lindl. | DEBI7 |
| n/a | Dendrobium discolor Lindl. | DEDI14 |
| n/a | Dendrobium linguiforme Sm. | DELI7 |
| n/a | Dendrobium scopa Lindl. [excluded] | DESC8 |
| n/a | Dendrophylax Reichenb. | DENDR15 |
| n/a | Dichromanthus Garay | DICHR3 |
| n/a | Didymoplexis fimbriata Schltr. | DIFI4 |
| n/a | Didymoplexis Griff. | DIDYM3 |
| n/a | Elleanthus linifolius K. Presl [excluded] | ELLI5 |
| n/a | Encyclia bifida (Aubl.) Britt. & P. Wilson [excluded] | ENBI3 |
| n/a | Encyclia fucata (Lindl.) Britt. & Millsp. [excluded] | ENFU2 |
| n/a | Encyclia rubra (Lindl.) Britt. & Millsp. [excluded] | ENRU6 |
| n/a | Epidendrum ?obrienianum Rolfe [evectum ? ibaguense] | EPOB2 |
| n/a | Epidendrum ibaguense Kunth [excluded] | EPIB |
| n/a | Epidendrum lacerum Lindl. [excluded] | EPLA7 |
| n/a | Epidendrum magnoliae Muhl. var. mexicanum (L.O. Williams) P.M. Brown | EPMAM2 |
| n/a | Epidendrum nutans Sw. [excluded] | EPNU |
| n/a | Epidendrum pallidiflorum Hook. [excluded] | EPPA10 |
| n/a | Epidendrum parkinsonianum Hook. | EPPA9 |
| n/a | Epidendrum patens Sw. [excluded] | EPPA11 |
| n/a | Epidendrum pseudoramosum Schlechter [excluded] | EPPS2 |
| n/a | Epidendrum serrulatum Sw. [excluded] | EPSE7 |
| n/a | Eulophia graminea Lindl. | EUGR19 |
| n/a | Eulophia macgregorii Ames | EUMA28 |
| n/a | Eulophia pulchra (Thouars) Lindl. | EUPU20 |
| n/a | Geodorum densiflorum (Lam.) Schltr. | GEDE11 |
| n/a | Geodorum Jacks. | GEODO |
| n/a | Habenaria floribunda Lindl. [excluded] | HAFL8 |
| n/a | Habenaria rodeiensis Barb. Rodr. | HARO3 |
| n/a | Laelia harpophylla Rchb. F. | LAHA3 |
| n/a | Liparis ?jonesii S. Bentley [liliifolia ? loeselii] | LIJO2 |
| n/a | Liparis guamensis Ames | LIGU |
| n/a | Liparis harrisii Fawcett & Rendle [excluded] | LIHA7 |
| n/a | Listera ?veltmanii Case [auriculata ? convallarioides] | LIVE4 |
| n/a | Malaxis monophyllos (L.) Sw. [excluded] | MAMO9 |
| n/a | Masdevallia coccinea Linden ex Lindl. | MACO34 |
| n/a | Maxillaria luteo-alba Lindl. | MALU5 |
| n/a | Miltonia vexillaria (Rchb. f.) G. Nicholson | MIVE6 |
| n/a | Nervilia aragoana Gaudich. | NEAR3 |
| n/a | Nervilia Comm. ex Gaudich. | NERVI |
| n/a | Nervilia jacksoniae Rinehart & Fosberg | NEJA3 |
| n/a | Nervilia platychila Schltr. | NEPL2 |
| n/a | Odontoglossum triumphans Rchb. F. & Warsz. | ODTR |
| n/a | Oncidium cebolleta (Jacq.) Sw. [excluded] | ONCE2 |
| n/a | Oncidium lemonianum Lindl. [excluded] | ONLE3 |
| n/a | Oncidium papilio Lindl. [excluded] | ONPA4 |
| n/a | Orchis purpurella T.& T.A. Steph. [excluded] | ORPU15 |
| n/a | Platanthera ?andrewsii (M. White) Luer [lacera ? psycodes] | PLAN |
| n/a | Platanthera ?bicolor (Raf.) Luer (pro sp.) [blephariglottis ? ciliaris] | PLBI |
| n/a | Platanthera ?canbyi (Ames) Luer [blephariglottis ? cristata] | PLCA8 |
| n/a | Platanthera ?channellii J.P. Folsom [ciliaris ? cristata] | PLCH5 |
| n/a | Platanthera ?correllii Schrenk [hyperborea ? stricta] | PLCO23 |
| n/a | Platanthera ?estesii Schrenk [dilatata ? stricta] | PLES3 |
| n/a | Platanthera ?keenanii P.M. Brown [grandiflora ? lacera] | PLKE |
| n/a | Platanthera ?lassenii Schrenk [dilatata ? sparsiflora] | PLLA13 |
| n/a | Platanthera ?media (Rydb.) Luer (pro sp.) [dilatata ? hyperborea] | PLME2 |
| n/a | Platanthera ?vossii Case [blephariglottis ? clavellata] | PLVO |
| n/a | Platanthera obtusata (Banks ex Pursh) Lindl. ssp. oligantha (Turcz.) Hult | PLOBO2 |
| n/a | Pleurothallis odontopetala Reichenb. f. [excluded] | PLOD3 |
| n/a | Pleurothallis quadrifida (Llave & Lex.) Lindl. [excluded] | PLQU3 |
| n/a | Prosthechea cochleata (L.) W.E. Higgins var. triandra (Ames) W.E. Higgins | PRCOT |
| n/a | Prosthechea Kn. & Westc. | PROST |
| n/a | Psychilis ?raganii Sauleda [kraenzlinii ? krugii] | PSRA2 |
| n/a | Renanthera monachica Ames | REMO3 |
| n/a | Restrepiella Garay & Dunst. | RESTR2 |
| n/a | Restrepiella ophiocephala (Lindl.) Garay & Dunsterville [excluded] | REOP2 |
| n/a | Schiedeella Schlechter | SCHIE2 |
| n/a | Sobralia macrantha Lindl. | SOMA10 |
| n/a | Spathoglottis carolinensis Schltr. | SPCA19 |
| n/a | Spathoglottis elmeri Ames [excluded] | SPEL4 |
| n/a | Spathoglottis micronesiaca Schltr. | SPMI16 |
| n/a | Spiranthes ?borealis P.M. Brown [casei ? ochroleuca] | SPBO3 |
| n/a | Spiranthes ?folsomii P.M. Brown [longilabris ? odorata] | SPFO5 |
| n/a | Spiranthes ?intermedia Ames [lacera ? vernalis] | SPIN6 |
| n/a | Spiranthes ?itchetuckneensis P.M. Brown [ovalis ? odorata] | SPIT |
| n/a | Spiranthes ?meridionalis P.M. Brown [praecox ? vernalis] | SPME6 |
| n/a | Spiranthes ?simpsonii Catling & Sheviak [lacera ? romanzoffiana] | SPSI6 |
| n/a | Spiranthes bicolor (Ker-Gawl.) Lindl. [excluded] | SPBI5 |
| n/a | Spiranthes lanceolata (Aubl.) L?on var. luteoalba (Reichenb. f.) Luer [excluded] | SPLAL4 |
| n/a | Stenorrhynchos squamulosum (Kunth) Spreng. | STSQ2 |
| n/a | Trichocentrum Poepp. & Endl. | TRICH27 |
| n/a | Vanda tricolor Hook. | VATR3 |
| n/a | Xylobium Lindl. | XYLOB2 |
| n/a | Xylobium palmifolium (Sw.) Benth. [excluded] | XYPA7 |
| n/a | Zeuxine fritzii Schltr. | ZEFR |
| Acuna's star orchid | Epidendrum acunae Dressler | EPAC |
| Adam and Eve | Aplectrum hyemale (Muhl. ex Willd.) Torr. | APHY |
| Adam and Eve | Aplectrum Torr. | APLEC |
| adder's-mouth orchid | Malaxis Soland. ex Sw. | MALAX |
| alcove bog orchid | Platanthera zothecina (Higgins & Welsh) Kartesz & Gandhi | PLZO |
| Aleutian adder's-mouth orchid | Malaxis diphyllos Cham. | MADI5 |
| Aleutian bog orchid | Platanthera tipuloides (L.) Lindl. | PLTI |
| Aleutian bog orchid | Platanthera tipuloides (L.) Lindl. var. behringiana (Rydb.) Hult | PLTIB |
| amerorchis | Amerorchis Hult | AMERO |
| Amerorchis rotundifolia | Orchis rotundifolia Banks ex Pursh | ORRO3 |
| Amerorchis rotundifolia | Orchis rotundifolia Banks ex Pursh var. lineata Mousley | ORROL |
| Ames's lady's tresses | Spiranthes amesiana Schlechter | SPAM7 |
| anoectochilus | Anoectochilus Blume | ANOEC |
| Anoectochilus sandvicensis | Anoectochilus apiculatus L.O. Williams & Fosberg | ANAP3 |
| Antilles star orchid | Epidendrum antillanum Ackerman & H?gsater | EPAN6 |
| arboreal bentspur orchid | Campylocentrum fasciolum (Lindl.) Cogn. | CAFA2 |
| arboreal leafystem orchid | Dichaea hystricina Reichenb. f. | DIHY |
| Arizona adder's-mouth orchid | Malaxis tenuis (S. Wats.) Ames | MATE2 |
| Arundina graminifolia | Arundina bambusifolia (Roxb.) Lindl. | ARBA3 |
| Ash Meadows lady's tresses | Spiranthes infernalis Sheviak | SPIN7 |
| auricled twayblade | Listera auriculata Wieg. | LIAU2 |
| autumn coralroot | Corallorhiza odontorhiza (Willd.) Poir. | COOD7 |
| autumn coralroot | Corallorhiza odontorhiza (Willd.) Poir. var. odontorhiza | COODO2 |
| autumn coralroot | Corallorhiza odontorhiza (Willd.) Poir. var. pringlei (Greenm.) Freudenstein | COODP2 |
| babyboot orchid | Lepanthes Sw. | LEPAN |
| bamboo orchid | Arundina Blume | ARUND |
| bamboo orchid | Arundina graminifolia (D. Don) Hochr. | ARGR6 |
| basiphyllaea | Basiphyllaea Schlechter | BASIP |
| Basiphyllaea corallicola | Basiphyllaea angustifolia Schlechter | BAAN2 |
| Basiphyllaea corallicola | Carteria corallicola Small | CACO84 |
| Bayard's adder's-mouth orchid | Malaxis bayardii Fern. | MABA6 |
| bearded grasspink | Calopogon barbatus (Walt.) Ames | CABA |
| bee orchid | Lycaste barringtoniae (Sm.) Lindl. | LYBA2 |
| Beloglottis costaricensis | Spiranthes costaricensis Reichenb. f. | SPCO6 |
| Bentley's coralroot | Corallorhiza bentleyi Freudenstein | COBE7 |
| bentspur orchid | Campylocentrum Benth. | CAMPY2 |
| Beyrich's hooded orchid | Galeandra bicarinata G.A. Romero & P.M. Brown | GABI6 |
| big cypress star orchid | Epidendrum strobiliferum Reichenb. f. | EPST2 |
| big-horn bog orchid | Habenaria macroceratitis Willd. | HAMA10 |
| big-mouth star orchid | Epidendrum amphistomum A. Rich. | EPAM3 |
| bletia | Bletia Ruiz & Pav?n | BLETI |
| bletilla | Bletilla Reichenb. f. | BLETI2 |
| blue orchid | Vanda coeralea Griff. Ex Lindl. | VACO7 |
| bluntleaved orchid | Platanthera obtusata (Banks ex Pursh) Lindl. | PLOB |
| bluntleaved orchid | Platanthera obtusata (Banks ex Pursh) Lindl. ssp. obtusata | PLOBO3 |
| bog adder's-mouth orchid | Malaxis paludosa (L.) Sw. | MAPA4 |
| bog orchid | Habenaria Willd. | HABEN |
| bonnet orchid | Pleurothallis R. Br. ex Ait. f. | PLEUR3 |
| bonnet orchid | Trichosalpinx Luer | TRICH24 |
| brassavola | Brassavola R. Br. ex Ait. f. | BRASS3 |
| Brassavola cucullata | Epidendrum cucullatum L. | EPCU3 |
| Brassavola nodosa | Epidendrum nodosum L. | EPNO2 |
| brassia | Brassia R. Br. ex Ait. f. | BRASS4 |
| Britton's shadow witch | Ponthieva brittoniae Ames | POBR9 |
| broadleaf helleborine | Epipactis helleborine (L.) Crantz | EPHE |
| broadleaf noddingcaps | Triphora amazonica Schlechter | TRAM18 |
| broadlipped twayblade | Listera convallarioides (Sw.) Nutt. ex Ell. | LICO5 |
| broughtonia | Broughtonia R. Brown | BROUG |
| Broughtonia domingensis | Laeliopsis domingensis (Lindl.) Lindl. | LADO |
| brown widelip orchid | Liparis liliifolia (L.) L.C. Rich. ex Ker-Gawl. | LILI3 |
| brown-flower butterfly orchid | Epidendrum anceps Jacq. | EPAN3 |
| bulbophyllum | Bulbophyllum Thouars | BULBO2 |
| Bulbophyllum pachyrrachis | Bolbophyllaria pachyrrachis (A. Rich.) Reichenb. f. | BOPA5 |
| Bulbophyllum pachyrrachis | Pleurothallis pachyrrachis A. Rich | PLPA8 |
| butterfly orchid | Encyclia Hook. | ENCYC |
| butterfly orchid | Psychopsis papilio (Lindl.) H.G. Jones | PSPA9 |
| butterfly orchid | Psychopsis Raf. | PSYCH3 |
| caelogyne | Caelogyne Lindl. | CAELO2 |
| California lady's slipper | Cypripedium californicum Gray | CYCA4 |
| Calopogon barbatus | Limodorum parviflorum (Lindl.) Nash | LIPA11 |
| Calopogon multiflorus | Limodorum multiflorum (Lindl.) C. Mohr | LIMU5 |
| Calopogon multiflorus | Limodorum pinetorum Small | LIPI4 |
| Calopogon pallidus | Limodorum pallidum (Chapman) C. Mohr | LIPA14 |
| Calopogon tuberosus var. simpsonii | Limodorum simpsonii (Chapman) Small | LISI3 |
| Calopogon tuberosus var. tuberosus | Calopogon pulchellus R. Br. ex Ait. f. | CAPU23 |
| Calopogon tuberosus var. tuberosus | Calopogon pulchellus R. Br. ex Ait. f. var. latifolius (St. John) Fern. | CAPUL3 |
| Calopogon tuberosus var. tuberosus | Calopogon tuberosus (L.) B.S.P. var. latifolius (St. John) Boivin | CATUL |
| Calopogon tuberosus var. tuberosus | Limodorum tuberosum L. | LITU4 |
| Calypso bulbosa var. americana | Cytherea bulbosa (L.) House p.p. | CYBU5 |
| Calypso bulbosa var. occidentalis | Calypso bulbosa (L.) Oakes ssp. occidentalis (Holz.) Calder & Taylor | CABUO2 |
| Campylocentrum fasciolum | Campylocentrum sullivanii Fawcett & Rendle | CASU29 |
| Campylocentrum filiforme | Campylocentrum monteverde (Reichenb. f.) Rolfe | CAMO19 |
| Campylocentrum filiforme | Harrisella filiformis (Sw.) Cogn. | HAFI |
| Campylocentrum micranthum | Campylocentrum jamaicense (Reichenb. f.) Benth. | CAJA4 |
| Canelo lady's tresses | Spiranthes graminea Lindl. [excluded] | SPGR5 |
| Cape Sable orchid | Trichocentrum maculatum (Aubl.) M. Chase | TRMA19 |
| Caribbean false helmetorchid | Erythrodes plantaginea (L.) Fawcett & Rendle | ERPL4 |
| Caribbean jug orchid | Platythelys sagraeanus (A. Rich.) Garay | PLSA11 |
| Carite babyboot orchid | Lepanthes caritensis Tremblay & Ackerman | LECA55 |
| Carter's orchid | Basiphyllaea corallicola (Small) Ames | BACO2 |
| Case's lady's tresses | Spiranthes casei Catling & Cruise | SPCA6 |
| Case's lady's tresses | Spiranthes casei Catling & Cruise var. casei | SPCAC4 |
| catasetum | Catasetum Rich. ex Kunth | CATAS2 |
| cattleya | Cattleya Lindl. | CATTL2 |
| cephalanthera | Cephalanthera L.C. Rich. | CEPHA3 |
| Cephalanthera austiniae | Eburophyton austiniae (Gray) Heller | EBAU2 |
| Chapman's fringed orchid | Platanthera chapmanii (Small) Luer | PLCH2 |
| checkered rattlesnake plantain | Goodyera tesselata Lodd. | GOTE |
| Chimissso's orchid | Platanthera chorisiana (Cham.) Reichenb. | PLCH3 |
| Chiricahua adder's-mouth orchid | Malaxis soulei L.O. Williams | MASO8 |
| Chisos Mountain crested coralroot | Hexalectris revoluta Correll | HERE2 |
| clamshell orchid | Prosthechea cochleata (L.) W.E. Higgins | PRCO4 |
| clamshell orchid | Prosthechea cochleata (L.) W.E. Higgins var. cochleata | PRCOC |
| Cleistes bifaria | Cleistes divaricata (L.) Ames var. bifaria Fern. | CLDIB |
| Cleistes bifaria | Pogonia bifaria (Fern.) P.M. Brown & Wunderlin | POBI18 |
| Cleistes divaricata | Pogonia divaricata (L.) R. Br. ex Ait. f. | PODI9 |
| clustered lady's slipper | Cypripedium fasciculatum Kellogg ex S. Wats. | CYFA |
| Cochise adder's-mouth orchid | Malaxis porphyrea (Ridley) Kuntze | MAPO15 |
| cochleanthes | Cochleanthes Raf. | COCHL2 |
| Cochleanthes flabelliformis | Warscewiczella flabelliformis (Sw.) Cogn. | WAFL |
| Coleman's piperia | Piperia colemanii R. Morgan & Glicenstein | PICO8 |
| Colombian bonnet orchid | Trichosalpinx dura (Lindl.) Luer | TRDU5 |
| comparettia | Comparettia Poepp. & Endl. | COMPA |
| confusing lady's tresses | Deiregyne confusa Garay | DECO12 |
| Cooper's rein orchid | Piperia cooperi (S. Wats.) Rydb. | PICO9 |
| Coot Bay dancing-lady orchid | Oncidium carthaginense (Jacq.) Sw. [excluded] | ONCA |
| Corallorhiza | Corallorrhiza Gagnebin [orthographic variant] | CORAL2 |
| Corallorhiza maculata | Corallorrhiza maculata (Raf.) Raf. [orthographic variant] | COMA4 |
| Corallorhiza maculata var. maculata | Corallorhiza maculata (Raf.) Raf. var. flavida (Peck) Cockerell | COMAF2 |
| Corallorhiza maculata var. maculata | Corallorhiza multiflora Nutt. | COMU11 |
| Corallorhiza maculata var. maculata | Corallorrhiza maculata (Raf.) Raf. var. flavida (M.E. Peck) Cockerell [orthographic variant] | COMAF |
| Corallorhiza maculata var. maculata | Corallorrhiza maculata (Raf.) Raf. var. maculata (Raf.) Raf. [orthographic variant] | COMAM5 |
| Corallorhiza maculata var. maculata | Corallorrhiza multiflora Nutt. [orthographic variant] | COMU5 |
| Corallorhiza maculata var. occidentalis | Corallorhiza maculata (Raf.) Raf. ssp. occidentalis (Lindl.) Cockerell | COMAO4 |
| Corallorhiza maculata var. occidentalis | Corallorhiza maculata (Raf.) Raf. var. immaculata M.E. Peck | COMAI3 |
| Corallorhiza maculata var. occidentalis | Corallorhiza maculata (Raf.) Raf. var. intermedia Farw. | COMAI4 |
| Corallorhiza maculata var. occidentalis | Corallorhiza maculata (Raf.) Raf. var. punicea Bartlett | COMAP4 |
| Corallorhiza maculata var. occidentalis | Corallorrhiza maculata (Raf.) Raf. ssp. occidentalis (Lindl.) Cockerell [orthographic variant] | COMAO3 |
| Corallorhiza maculata var. occidentalis | Corallorrhiza maculata (Raf.) Raf. var. immaculata M.E. Peck [orthographic variant] | COMAI |
| Corallorhiza maculata var. occidentalis | Corallorrhiza maculata (Raf.) Raf. var. intermedia Farw. [orthographic variant] | COMAI2 |
| Corallorhiza maculata var. occidentalis | Corallorrhiza maculata (Raf.) Raf. var. occidentalis (Lindl.) Ames [orthographic variant] | COMAO |
| Corallorhiza maculata var. occidentalis | Corallorrhiza maculata (Raf.) Raf. var. punicea Bartlett [orthographic variant] | COMAP2 |
| Corallorhiza mertensiana | Corallorhiza maculata (Raf.) Raf. ssp. mertensiana (Bong.) Calder & Taylor | COMAM6 |
| Corallorhiza mertensiana | Corallorrhiza maculata (Raf.) Raf. ssp. mertensiana (Bong.) Calder & Taylor [orthographic variant] | COMAM4 |
| Corallorhiza mertensiana | Corallorrhiza mertensiana Bong. [orthographic variant] | COME4 |
| Corallorhiza odontorhiza | Corallorrhiza odontorhiza (Willd.) Poir. [orthographic variant] | COOD |
| Corallorhiza odontorhiza var. odontorhiza | Corallorhiza micrantha Chapman | COMI17 |
| Corallorhiza odontorhiza var. odontorhiza | Corallorrhiza micrantha Chapman [orthographic variant] | COMI7 |
| Corallorhiza odontorhiza var. odontorhiza | Corallorrhiza odontorhiza (Willd.) Poir. var. odontorhiza (Willd.) Poir. [orthographic variant] | COODO |
| Corallorhiza odontorhiza var. pringlei | Corallorrhiza odontorhiza (Willd.) Poir. var. pringlei (Greenm.) Freudenstein [orthographic variant] | COODP |
| Corallorhiza striata | Corallorrhiza striata Lindl. [orthographic variant] | COST |
| Corallorhiza striata var. striata | Corallorhiza ochroleuca Rydb. | COOC10 |
| Corallorhiza striata var. striata | Corallorhiza striata Lindl. var. flavida Todsen & Todsen | COSTF2 |
| Corallorhiza striata var. striata | Corallorhiza striata Lindl. var. ochroleuca (Rydb.) Magrath | COSTO4 |
| Corallorhiza striata var. striata | Corallorrhiza ochroleuca Rydb. [orthographic variant] | COOC7 |
| Corallorhiza striata var. striata | Corallorrhiza striata Lindl. var. flavida Todsen & Todsen [orthographic variant] | COSTF |
| Corallorhiza striata var. striata | Corallorrhiza striata Lindl. var. ochroleuca (Rydb.) Magrath [orthographic variant] | COSTO3 |
| Corallorhiza striata var. striata | Corallorrhiza striata Lindl. var. striata Lindl. [orthographic variant] | COSTS |
| Corallorhiza striata var. vreelandii | Corallorhiza bigelovii S. Wats. | COBI13 |
| Corallorhiza striata var. vreelandii | Corallorrhiza bigelovii S. Wats. [orthographic variant] | COBI11 |
| Corallorhiza striata var. vreelandii | Corallorrhiza striata Lindl. var. vreelandii (Rydb.) L.O. Williams [orthographic variant] | COSTV |
| Corallorhiza trifida | Corallorhiza corallorhiza (L.) Karst. | COCO40 |
| Corallorhiza trifida | Corallorhiza trifida Chatelain var. verna (Nutt.) Fern. | COTRV2 |
| Corallorhiza trifida | Corallorrhiza corallorrhiza (L.) Karst. [orthographic variant] | COCO23 |
| Corallorhiza trifida | Corallorrhiza trifida Chatelain var. verna (Nutt.) Fern. [orthographic variant] | COTRV |
| Corallorhiza trifida | Corallorrhiza trifida Chatelain [orthographic variant] | COTR3 |
| Corallorhiza wisteriana | Corallorrhiza wisteriana Conrad [orthographic variant] | COWI2 |
| coralroot | Corallorhiza Gagnebin | CORAL5 |
| Costa Rican lady's tresses | Beloglottis costaricensis (Reichenb. f.) Schlechter | BECO5 |
| cowhorn orchid | Cyrtopodium punctatum (L.) Lindl. | CYPU4 |
| Craighead's noddingcaps | Triphora craigheadii Luer | TRCR4 |
| cranichis-like ladies'-tresses | Cyclopogon cranichoides (Griseb.) Schlechter | CYCR10 |
| creamy lady's tresses | Spiranthes porrifolia Lindl. | SPPO7 |
| crested coralroot | Hexalectris Raf. | HEXAL |
| crested yellow orchid | Platanthera cristata (Michx.) Lindl. | PLCR |
| cricket orchid | Brassia caudata (L.) Lindl. | BRCA7 |
| crippled cranefly | Tipularia discolor (Pursh) Nutt. | TIDI |
| crow orchid | Corymborkis Thouars | CORYM2 |
| Cuban false helmetorchid | Erythrodes hirtella (Sw.) Fawcett & Rendle | ERHI6 |
| Cuban Prescott orchid | Prescotia pellucida Lindl. | PRPE4 |
| cup orchid | Brachionidium Lindl. | BRACH4 |
| custard orchid | Eurystyles ananassocomos (Reichenb. f.) Schlechter | EUAN8 |
| custard orchid | Eurystyles Wawra | EURYS2 |
| Cyclopogon cranichoides | Beadlea cranichoides (Griseb.) Small | BECR |
| Cyclopogon cranichoides | Spiranthes cranichoides (Griseb.) Cogn. | SPCR2 |
| Cyclopogon elatus | Beadlea elata (Sw.) Small | BEEL |
| Cyclopogon elatus | Spiranthes elata (Sw.) L.C. Rich. | SPEL2 |
| cymbidium | Cymbidium Sw. | CYMBI |
| cypress-knee helmet orchid | Cranichis muscosa Sw. | CRMU3 |
| Cypripedium ?andrewsii var. favillianum | Cypripedium ?favillianum J.T. Curtis | CYFA4 |
| Cypripedium ?andrewsii var. landonii | Cypripedium ?landonii Gray (pro sp.) | CYLA15 |
| Cypripedium acaule | Fissipes acaulis (Ait.) Small | FIAC |
| Cypripedium arietinum | Criosanthes arietina (Ait. f.) House | CRAR11 |
| Cypripedium guttatum | Cypripedium guttatum Sw. var. guttatum Sw. [superfluous autonym] | CYGUG |
| Cypripedium parviflorum var. makasin | Cypripedium pubescens Willd. var. makasin Farw. | CYPUM |
| Cypripedium parviflorum var. parviflorum | Cypripedium calceolus L. ssp. parviflorum (Salisb.) Hult | CYCAP3 |
| Cypripedium parviflorum var. parviflorum | Cypripedium calceolus L. var. parviflorum (Salisb.) Fern. | CYCAP |
| Cypripedium parviflorum var. pubescens | Cypripedium calceolus L. var. planipetalum (Fern.) Victorin & Rouss. | CYCAP4 |
| Cypripedium parviflorum var. pubescens | Cypripedium calceolus L. var. pubescens (Willd.) Correll | CYCAP2 |
| Cypripedium parviflorum var. pubescens | Cypripedium furcatum Raf. | CYFU7 |
| Cypripedium parviflorum var. pubescens | Cypripedium pubescens Willd. | CYPU10 |
| Cypripedium parviflorum var. pubescens | Cypripedium pubescens Willd. var. pubescens Willd. [superfluous autonym] | CYPUP |
| Cypripedium passerinum | Cypripedium passerinum Richards. var. minganense Victorin | CYPAM2 |
| Cypripedium yatabeanum | Cypripedium guttatum Sw. ssp. yatabeanum (Makino) Hult | CYGUY2 |
| Cypripedium yatabeanum | Cypripedium guttatum Sw. var. yatabeanum (Makino) Pfitzer | CYGUY |
| cyrtopodium | Cyrtopodium R. Br. ex Ait. f. | CYRTO2 |
| Cyrtopodium polyphyllum | Cyrtopodium glutiniferum auct. non Raddi [misapplied] | CYGL9 |
| Cyrtopodium polyphyllum | Cyrtopodium paranaense Schlechter | CYPA28 |
| Dactylorhiza aristata var. aristata | Orchis aristata Fisch. ex Lindl. | ORAR |
| Dactylorhiza viridis | Coeloglossum bracteatum (Muhl. ex Willd.) Parl. | COBR3 |
| Dactylorhiza viridis | Coeloglossum viride (L.) Hartman | COVI6 |
| Dactylorhiza viridis | Coeloglossum viride (L.) Hartman ssp. bracteatum (Muhl. ex Willd.) Hult | COVIB3 |
| Dactylorhiza viridis | Coeloglossum viride (L.) Hartman var. islandicum (Lindl.) Schulze | COVII |
| Dactylorhiza viridis | Coeloglossum viride (L.) Hartman var. virescens (Muhl. ex Willd.) Luer | COVIV |
| Dactylorhiza viridis | Coeloglossum viride (L.) Hartman var. viride (L.) Hartman [superfluous autonym] | COVIV2 |
| Dactylorhiza viridis | Habenaria bracteata (Muhl. ex Willd.) R. Br. ex Ait. f. | HABR7 |
| Dactylorhiza viridis | Habenaria viridis (L.) R. Br. ex Ait. f. | HAVI7 |
| Dactylorhiza viridis | Habenaria viridis (L.) R. Br. ex Ait. f. var. bracteata (Muhl. ex Willd.) Reichenb. ex Gray | HAVIB2 |
| Dactylorhiza viridis | Habenaria viridis (L.) R. Br. ex Ait. f. var. interjecta Fern. | HAVII |
| daddy longlegs orchid | Brassavola cucullata (L.) R. Br. ex Ait. f. | BRCU |
| dancing-lady orchid | Oncidium Sw. | ONCID |
| dancing-lady orchid | Tolumnia G.J. Braem | TOLUM |
| Deiregyne confusa | Deiregyne durangensis (Ames & C. Schweinf.) Garay | DEDU |
| Deiregyne confusa | Spiranthes confusa (Garay) Kartesz & Gandhi | SPCO15 |
| Deiregyne confusa | Spiranthes durangensis Ames & C. Schweinf. | SPDU |
| delicate violet orchid | Ionopsis utricularioides (Sw.) Lindl. | IOUT |
| dendrobium | Dendrobium Sw. | DENDR13 |
| Dendrophylax lindenii | Polyradicion lindenii (Lindl.) Garay | POLI4 |
| Dendrophylax lindenii | Polyrrhiza lindenii (Lindl.) Cogn. | POLI3 |
| denseflower rein orchid | Piperia elongata Rydb. | PIEL4 |
| Dichaea latifolia | Dichaea muricata auct. non (Sw.) Lindl. p.p. [misapplied] | DIMU3 |
| Dichaea pendula | Dichaea echinocarpa (Sw.) Lindl. | DIEC |
| Dichaea pendula | Dichaea swartzii (C. Schweinf.) Garay & Sweet | DISW2 |
| Dichromanthus cinnabarinus | Spiranthes cinnabarina (Llave & Lex.) Hemsl. | SPCI |
| dilomilis | Dilomilis Raf. | DILOM |
| Dilomilis montana | Octadesmia montana (Sw.) Benth. | OCMO2 |
| dollar orchid | Prosthechea boothiana (Lindl.) W.E. Higgins | PRBO3 |
| dollar orchid | Prosthechea boothiana (Lindl.) W.E. Higgins var. erythronioides (Small) W.E. Higgins | PRBOE |
| domingoa | Domingoa Schlechter | DOMIN |
| Domingoa haematochila | Domingoa hymenodes (Reichenb. f.) Schlechter | DOHY |
| dotted orchid | Helleriella punctulata (Reichenb. f.) Garay & Sweet | HEPU15 |
| downy rattlesnake plantain | Goodyera pubescens (Willd.) R. Br. ex Ait. f. | GOPU |
| dragon's mouth | Arethusa bulbosa L. | ARBU |
| dragon's mouth | Arethusa L. | ARETH |
| dwarf butterfly orchid | Prosthechea pygmaea (Hook.) W.E. Higgins | PRPY |
| Eaton's lady's tresses | Spiranthes eatonii Ames ex P.M. Brown | SPEA |
| Ehrenberg's adder's-mouth orchid | Malaxis ehrenbergii (Reichenb. f.) Kuntze [excluded] | MAEH |
| elegant piperia | Piperia elegans (Lindl.) Rydb. | PIEL2 |
| elegant piperia | Piperia elegans (Lindl.) Rydb. ssp. decurtata R. Morgan & Glicenstein | PIELD2 |
| elegant piperia | Piperia elegans (Lindl.) Rydb. ssp. elegans | PIELE4 |
| eltroplectris | Eltroplectris Raf. | ELTRO |
| Eltroplectris calcarata | Centrogenium setaceum (Lindl.) Schlechter | CESE3 |
| Eltroplectris calcarata | Eltroplectris acuminata Raf. nom. illeg. | ELAC3 |
| Eltroplectris calcarata | Pelexia setacea Lindl. | PESE16 |
| Encyclia bifida | Encyclia papilionacea (Vahl) Schlechter [excluded] | ENPA4 |
| Encyclia bifida | Epidendrum bifidum Aubl. [excluded] | EPBI5 |
| Encyclia bifida | Epidendrum brittonianum A.D. Hawkes [excluded] | EPBR5 |
| Encyclia bifida | Epidendrum fucatum Lindl. [excluded] | EPFU3 |
| Encyclia gravida | Encyclia sintenisii (Reichenb. f.) Britt. | ENSI |
| Encyclia gravida | Epidendrum oncidioides Lindl. var. gravidum (Lindl.) Ames | EPONG |
| Encyclia gravida | Epidendrum sintenisii Reichenb. f. | EPSI |
| Encyclia isochila | Epidendrum belvederense Fawcett & Rendle | EPBE2 |
| Encyclia isochila | Epidendrum isochilum Reichenb. f. var. tridens Reichenb. f. | EPIST |
| Encyclia tampensis | Epidendrum tampense Lindl. | EPTA |
| Epidendrum acunae | Epidendrum blancheanum auct. non Urban [misapplied] | EPBL |
| Epidendrum amphistomum | Amphiglottis anceps auct. non (Jacq.) Britt. & P. Wilson [misapplied] | AMAN4 |
| Epidendrum amphistomum | Epidendrum anceps auct. non Jacq. [misapplied] | EPAN7 |
| Epidendrum anceps | Amphiglottis anceps (Jacq.) Britt. & P. Wilson | AMAN3 |
| Epidendrum boricuarum | Amphiglottis difformis auct. non (Jacq.) Britt. [misapplied] | AMDI2 |
| Epidendrum boricuarum | Epidendrum difforme auct. non Jacq. [misapplied] | EPDI |
| Epidendrum boricuarum | Epidendrum latifolium (Lindl.) Garay & Sweet | EPLA4 |
| Epidendrum boricuarum | Epidendrum moirianum auct. non A.D. Hawkes [misapplied] | EPMO |
| Epidendrum boricuarum | Neolehmannia difformis auct. non (Jacq.) Pabst [misapplied] | NEDI |
| Epidendrum ciliare | Auliza ciliaris (L.) Salisb. | AUCI2 |
| Epidendrum jamaicense | Amphiglottis corymbosa auct. non (Lindl.) Britt. [misapplied] | AMCO8 |
| Epidendrum lacerum | Amphiglottis lacera (Lindl.) Britt. [excluded] | AMLA12 |
| Epidendrum magnoliae var. magnoliae | Amphiglottis conopsea (Ait. f.) Small | AMCO7 |
| Epidendrum magnoliae var. magnoliae | Epidendrum conopseum Ait. f. | EPCO4 |
| Epidendrum magnoliae var. mexicanum | Epidendrum conopseum Ait. f. var. mexicana L.O. Williams | EPCOM |
| Epidendrum miserrimum | Jacquiniella miserrima (Reichenb. f.) Stehl | JAMI2 |
| Epidendrum nocturnum | Amphiglottis nocturna (Jacq.) Britt. | AMNO3 |
| Epidendrum pallidiflorum | Amphiglottis pallidiflora (Hook.) Britt. [excluded] | AMPA15 |
| Epidendrum ramosum | Spathiger ramosus (Jacq.) Britt. | SPRA2 |
| Epidendrum rigidum | Spathiger rigidus (Jacq.) Small | SPRI |
| Epidendrum secundum | Amphiglottis secunda (Jacq.) Salisb. | AMSE2 |
| Epidendrum strobiliferum | Spathiger strobilifera (Reichenb. f.) Small | SPST |
| Epidendrum vicentinum | Epidendropsis vicentina (Lindl.) Garay & Dunsterville | EPVI4 |
| Epipactis atrorubens | Epipactis rubiginosa Gaud. ex W.D.J. Koch | EPRU |
| Epipactis atrorubens | Serapias atrorubens O. Hoffmann | SEAT4 |
| Epipactis helleborine | Epipactis latifolia (L.) All. | EPLA5 |
| Epipactis helleborine | Serapias helleborine L. | SEHE6 |
| Erythrodes hirtella | Physurus hirtellus (Sw.) Lindl. | PHHI9 |
| Erythrodes plantaginea | Physurus plantagineus (L.) Lindl. | PHPL3 |
| Eulophia alta | Platypus altus (L.) Small | PLAL4 |
| fairy bentspur orchid | Campylocentrum micranthum (Lindl.) Maury | CAMI26 |
| fairy orchid | Nidema ottonis (Reichenb. f.) Britt. & Millsp. | NIOT |
| fairy slipper | Calypso bulbosa (L.) Oakes | CABU |
| fairy slipper | Calypso bulbosa (L.) Oakes var. americana (R. Br. ex Ait. f.) Luer | CABUA |
| fairy slipper | Calypso bulbosa (L.) Oakes var. occidentalis (Holz.) Boivin | CABUO |
| fairy slipper | Calypso Salisb. | CALYP |
| false helmetorchid | Erythrodes Blume | ERYTH2 |
| false tiger orchid | Elleanthus cordidactylus Ackerman | ELCO7 |
| fanshape orchid | Cochleanthes flabelliformis (Sw.) R.E. Schultes & Garay | COFL4 |
| fire star orchid | Epidendrum radicans Pav?n ex Lindley | EPRA2 |
| fiveleaf orchid | Isotria Raf. | ISOTR |
| flame orchid | Maxillaria coccinea (Jacq.) L.O. Williams ex Hodge | MACO8 |
| fleshy star orchid | Epidendrum boricuarum H?gsater & S?nchez | EPBO4 |
| fleshyleaf violet orchid | Ionopsis satyrioides (Sw.) Reichenb. f. | IOSA |
| flor de llanten | Pleurothallis gelida Lindl. | PLGE |
| flor de pasmo | Bletia patula Graham | BLPA |
| flor de pasmo | Bletia patula Graham var. alba A.D. Hawkes | BLPAA |
| flor de pasmo | Bletia patula Graham var. patula | BLPAP |
| Florida adder's-mouth orchid | Malaxis spicata Sw. | MASP2 |
| Florida Keys ladies'-tresses | Mesadenus lucayanus (Britt.) Schlechter | MELU3 |
| Florida lady's tresses | Spiranthes floridana (Wherry) Cory | SPFL10 |
| Florida orchid | Oncidium floridanum Ames | ONFL |
| Florida star orchid | Epidendrum floridense H?gsater | EPFL |
| fly orchid | Ophrys insectifera L. | OPIN2 |
| forest babyboot orchid | Lepanthes rubripetala Stimson | LERU5 |
| forest bonnet orchid | Pleurothallis aristata Hook. | PLAR4 |
| fragrant orchid | Gymnadenia conopsea (L.) R. Br. ex Ait. f. | GYCO |
| fringed orchid | Platanthera L.C. Rich. | PLATA2 |
| fringed star orchid | Epidendrum ciliare L. | EPCI2 |
| Galeandra bicarinata | Galeandra beyrichii auct. non Reichenb. f. [misapplied] | GABE2 |
| galearis | Galearis Raf. | GALEA2 |
| Galearis spectabilis | Galeorchis spectabilis (L.) Rydb. | GASP11 |
| Galearis spectabilis | Orchis spectabilis L. | ORSP2 |
| gentian noddingcaps | Triphora gentianoides (Sw.) Ames & Schlechter | TRGE |
| giant orchid | Pteroglossaspis ecristata (Fern.) Rolfe | PTEC2 |
| giantspiral lady's tresses | Spiranthes longilabris Lindl. | SPLO2 |
| Glass Mountain crested coralroot | Hexalectris nitida L.O. Williams | HENI2 |
| Goodyera oblongifolia | Goodyera decipiens (Hook.) F.T. Hubbard | GODE5 |
| Goodyera oblongifolia | Goodyera oblongifolia Raf. var. reticulata Boivin | GOOBR |
| Goodyera oblongifolia | Peramium decipiens (Hook.) Piper | PEDE14 |
| Goodyera oblongifolia | Peramium menziesii Lindl. | PEME61 |
| Goodyera pubescens | Peramium pubescens (Willd.) MacM. | PEPU20 |
| Goodyera repens | Goodyera ophioides (Fern.) Rydb. | GOOP |
| Goodyera repens | Goodyera repens (L.) R. Br. ex Ait. f. ssp. ophioides (Fern.) A. L?ve & Simon | GOREO3 |
| Goodyera repens | Goodyera repens (L.) R. Br. ex Ait. f. var. ophioides Fern. | GOREO2 |
| Goodyera repens | Peramium ophioides (Fern.) Rydb. | PEOP2 |
| Goodyera tesselata | Peramium tesselatum (Lodd.) Heller | PETE14 |
| govenia | Govenia Lindl. | GOVEN |
| Govenia floridana | Govenia liliacea auct. non Lindl. [misapplied] | GOLI3 |
| Govenia floridana | Govenia utriculata auct. non (Sw.) Lindl. [misapplied] | GOUT |
| grassleaf orchid | Koellensteinia graminea (Lindl.) Reichenb. f. | KOGR |
| grasspink | Calopogon R. Br. ex Ait. f. | CALOP2 |
| Great Plains lady's tresses | Spiranthes magnicamporum Sheviak | SPMA5 |
| Great Plains white fringed orchid | Platanthera praeclara Sheviak & Bowles | PLPR4 |
| greater purple fringed orchid | Platanthera grandiflora (Bigelow) Lindl. | PLGR2 |
| greater roundleaved orchid | Platanthera macrophylla (Goldie) P.M. Brown | PLMA9 |
| greater yellow lady's slipper | Cypripedium parviflorum Salisb. var. makasin (Farw.) Sheviak | CYPAM3 |
| greater yellow lady's slipper | Cypripedium parviflorum Salisb. var. pubescens (Willd.) Knight | CYPAP3 |
| greater yellowspike orchid | Polystachya concreta (Jacq.) Garay & Sweet | POCO27 |
| green adder's-mouth orchid | Malaxis unifolia Michx. | MAUN |
| green bonnet orchid | Pleurothallis ruscifolia (Jacq.) R. Br. ex Ait. f. | PLRU3 |
| green fly orchid | Epidendrum magnoliae Muhl. | EPMA3 |
| green fly orchid | Epidendrum magnoliae Muhl. var. magnoliae | EPMAM |
| green fringed orchid | Platanthera lacera (Michx.) G. Don | PLLA2 |
| green withe | Vanilla claviculata (W. Wright) Sw. | VACL |
| green-winged orchid | Orchis morio L. | ORMO5 |
| greenvein lady's tresses | Spiranthes praecox (Walt.) S. Wats. | SPPR2 |
| ground orchid | Spathoglottis Blume | SPATH2 |
| Guadeloupe bog orchid | Habenaria amalfitana Lehmann & Kr?nzlin | HAAM4 |
| Guadeloupe bonnet orchid | Pleurothallis domingensis Cogn. | PLDO |
| guilarte | Epidendrum vicentinum Lindl. | EPVI3 |
| gymnadenia | Gymnadenia R. Br. ex Ait. f. | GYMNA2 |
| Gymnadenia conopsea | Habenaria conopsea (L.) Benth. | HACO7 |
| Habenaria amalfitana | Habenaria dussii Cogn. | HADU |
| Habenaria macroceratitis | Habenaria habenaria (L.) Small | HAHA10 |
| Habenaria macroceratitis | Habenaria quinqueseta (Michx.) Eat. var. macroceratitis (Willd.) Luer | HAQUM2 |
| Habenaria odontopetala | Habenaria strictissima Reichenb. f. var. odontopetala (Reichenb. f.) L.O. Williams | HASTO |
| Habenaria odontopetala | Habenella odontopetala (Reichenb. f.) Small | HAOD2 |
| Habenaria repens | Platanthera repens (Nutt.) Wood | PLRE6 |
| hachuela | Pelexia adnata (Sw.) Spreng. | PEAD3 |
| hachuela | Pelexia Poit. ex Lindl. | PELEX |
| hairy bonnet orchid | Pleurothallis pubescens Lindl. ex Hook. | PLPU4 |
| hairy cup orchid | Brachionidium ciliolatum Garay | BRCI4 |
| hairy shadow witch | Ponthieva racemosa (Walt.) C. Mohr | PORA4 |
| hammock bog orchid | Habenaria distans Griseb. | HADI6 |
| hand bonnet orchid | Pleurothallis appendiculata Cogn. | PLAP |
| hapalorchis | Hapalorchis Schlechter | HAPAL |
| Hapalorchis lineatus | Hapalorchis tenuis (Lindl.) Schlechter | HATE4 |
| Hapalorchis lineatus | Spiranthes amabilis Ames | SPAM4 |
| Hapalorchis lineatus | Spiranthes fawcettii Cogn. | SPFA |
| Hapalorchis lineatus | Spiranthes lineata Lindl. | SPLI3 |
| harlequin dancing-lady orchid | Tolumnia variegata (Sw.) G.J. Braem | TOVA |
| harrisella | Harrisella Fawcett & Rendle | HARRI |
| Hassler's noddingcaps | Triphora hassleriana (Cogn.) Schlechter | TRHA7 |
| Hawai'i bog orchid | Platanthera holochila (Hbd.) Kraenzlin | PLHO4 |
| Hawai'i jeweled orchid | Anoectochilus sandvicensis Lindl. | ANSA2 |
| Hawai'i widelip orchid | Liparis hawaiensis auct. non Mann | LIHA2 |
| heartleaf twayblade | Listera cordata (L.) R. Br. ex Ait. f. | LICO6 |
| heartleaf twayblade | Listera cordata (L.) R. Br. ex Ait. f. var. cordata | LICOC2 |
| heartleaf twayblade | Listera cordata (L.) R. Br. ex Ait. f. var. nephrophylla (Rydb.) Hult | LICON |
| heavyfruit butterfly orchid | Encyclia gravida (Lindl.) Schlechter | ENGR |
| helleborine | Epipactis Zinn | EPIPA |
| helleriella | Helleriella A.D. Hawkes | HELLE2 |
| helmet orchid | Cranichis Sw. | CRANI |
| Hernando County noddingcaps | Triphora surinamensis (Lindl.) Britt. | TRSU4 |
| hidden orchid | Maxillaria crassifolia (Lindl.) Reichenb. f. | MACR2 |
| hooded coralroot | Corallorhiza striata Lindl. | COST19 |
| hooded coralroot | Corallorhiza striata Lindl. var. striata | COSTS3 |
| hooded lady's tresses | Spiranthes romanzoffiana Cham. | SPRO |
| hooded orchid | Galeandra Lindl. & F.A. Bayer | GALEA |
| Hooker's orchid | Platanthera hookeri (Torr. ex Gray) Lindl. | PLHO3 |
| Huachuca Mountain adder's-mouth orchid | Malaxis corymbosa (S. Wats.) Kuntze | MACO4 |
| Huron green orchid | Platanthera huronensis (Nutt.) Lindl. | PLHU2 |
| island babyboot orchid | Lepanthes dodiana Stimson | LEDO3 |
| island peacock orchid | Psychilis macconnelliae Sauleda | PSMA9 |
| isochilus | Isochilus R. Br. ex Ait. f. | ISOCH |
| Jamaican babyboot orchid | Lepanthes sanguinea Hook. | LESA3 |
| jug orchid | Platythelys querceticola (Lindl.) Garay | PLQU |
| Kentucky lady's slipper | Cypripedium kentuckiense C.F. Reed | CYKE2 |
| keyflower | Dactylorhiza aristata (Fisch. ex Lindl.) So? | DAAR |
| keyflower | Dactylorhiza aristata (Fisch. ex Lindl.) So? var. aristata | DAARA |
| keyflower | Dactylorhiza Neck. ex Nevski | DACTY3 |
| kidneyleaf twayblade | Listera smallii Wieg. | LISM |
| king orchid | Broughtonia domingensis (Lindl.) Rolfe | BRDO3 |
| Kodiak keyflower | Dactylorhiza aristata (Fisch. ex Lindl.) So? var. kodiakensis Luer & Luer f. | DAARK |
| koellensteinia | Koellensteinia Reichenb. f. | KOELL |
| Kraenzlin's peacock orchid | Psychilis kraenzlinii (Bello) Sauleda | PSKR |
| Krug's peacock orchid | Psychilis krugii (Bello) Sauleda | PSKR2 |
| lacelip lady's tresses | Spiranthes laciniata (Small) Ames | SPLA3 |
| ladies'-tresses | Cyclopogon K. Presl | CYCLO5 |
| ladies'-tresses | Mesadenus Schlechter | MESAD |
| ladies's bonnet orchid | Pleurothallis racemiflora Lindl. ex Hook. | PLRA2 |
| lady of the night orchid | Brassavola nodosa (L.) Lindl. | BRNO3 |
| lady orchid | Stenorrhynchos L.C. Rich. ex Spreng. | STENO10 |
| lady's slipper | Cypripedium L. | CYPRI |
| lady's tresses | Spiranthes L.C. Rich. | SPIRA2 |
| laelia | Laelia Lindl. | LAELI2 |
| large whorled pogonia | Isotria verticillata Raf. | ISVE |
| largeflower crested coralroot | Hexalectris grandiflora (A. Rich. & Gal.) L.O. Williams | HEGR9 |
| Latin American lady orchid | Stenorrhynchos speciosum (Jacq.) L.C. Rich. ex Spreng. | STSP16 |
| Latin American orchid | Oncidium ensatum Lindl. [excluded] | ONEN |
| lax-flowered green orchid | Platanthera gracilis Lindl. | PLGR6 |
| leach orchid | Stelis Sw. | STELI |
| leafless beaked lady orchid | Stenorrhynchos lanceolatum (Aubl.) L.C. Rich. | STLA11 |
| leafless beaked lady orchid | Stenorrhynchos lanceolatum (Aubl.) L.C. Rich. var. lanceolatum | STLAL5 |
| leafless beaked lady orchid | Stenorrhynchos lanceolatum (Aubl.) L.C. Rich. var. paludicola (Luer) Schrenk | STLAP2 |
| leafless bentspur orchid | Campylocentrum pachyrrhizum (Reichenb. f.) Rolfe | CAPA32 |
| leafless orchid | Wullschlaegelia aphylla (Sw.) Reichenb. f. | WUAP |
| leafless vanilla | Vanilla dilloniana Correll | VADI2 |
| leafy vanilla | Vanilla phaeantha Reichenb. f. | VAPH |
| leafystem orchid | Dichaea Lindl. | DICHA4 |
| leochilus | Leochilus Kn. & Westc. | LEOCH |
| lepanthopsis | Lepanthopsis Ames | LEPAN2 |
| Lepanthopsis melanantha | Lepanthes harrisii Fawcett & Rendle | LEHA4 |
| lesser purple fringed orchid | Platanthera psycodes (L.) Lindl. | PLPS2 |
| lesser rattlesnake plantain | Goodyera repens (L.) R. Br. ex Ait. f. | GORE2 |
| lesser roundleaved orchid | Platanthera orbiculata (Pursh) Lindl. | PLOR4 |
| lesser yellow lady's slipper | Cypripedium parviflorum Salisb. | CYPA19 |
| lesser yellow lady's slipper | Cypripedium parviflorum Salisb. var. parviflorum | CYPAP4 |
| lesser yellowspike orchid | Polystachya foliosa (Lindl. ex Hook.) Reichenb. f. | POFO4 |
| lime orchid | Corymborkis forcipigera (Reichenb. f. & Warszewicz) L.O. Williams | COFO7 |
| Liparis elata | Liparis eggersii Reichenb. f. | LIEG |
| Liparis elata | Liparis nervosa auct. non (Thunb.) Lindl. [misapplied] | LINE2 |
| lipped orchid | Leochilus labiatus (Sw.) Kuntze [excluded] | LELA42 |
| Listera auriculata | Neottia auriculata (Wieg.) Szlach. | NEAU |
| Listera auriculata | Ophrys auriculata (Wieg.) House | OPAU5 |
| Listera australis | Neottia australis (Lindl.) Szlach. | NEAU2 |
| Listera australis | Ophrys australis (Lindl.) House | OPAU6 |
| Listera borealis | Neottia borealis (Morong) Szlach. | NEBO2 |
| Listera caurina | Listera banksiana auct. non Lindl. [misapplied] | LIBA3 |
| Listera caurina | Neottia caurina (Piper) Szlach. | NECA9 |
| Listera caurina | Ophrys caurina (Piper) Rydb. | OPCA4 |
| Listera convallarioides | Ophrys convallarioides (Sw.) W. Wight | OPCO8 |
| Listera cordata var. cordata | Ophrys cordata L. | OPCO9 |
| Listera cordata var. nephrophylla | Listera cordata (L.) R. Br. ex Ait. f. ssp. nephrophylla (Rydb.) A.& D. L?ve | LICON2 |
| Listera cordata var. nephrophylla | Listera nephrophylla Rydb. | LINE5 |
| Listera cordata var. nephrophylla | Neottia nephrophylla (Rydb.) Szlach. | NENE6 |
| Listera smallii | Neottia smallii (Wieg.) Szlach. | NESM |
| Listera smallii | Ophrys smallii (Wieg.) House | OPSM |
| little lady's tresses | Spiranthes tuberosa Raf. | SPTU |
| longbract frog orchid | Dactylorhiza viridis (L.) A.M. Bateman, A.M. Pridgeon & M. Chase | DAVI6 |
| longclaw orchid | Eltroplectris calcarata (Sw.) Garay & Sweet | ELCA18 |
| longgland orchid | Macradenia lutescens R. Br. | MALU |
| longhorn bog orchid | Habenaria quinqueseta (Michx.) Eat. | HAQU |
| lopsided star orchid | Epidendrum secundum Jacq. | EPSE2 |
| Luquillo Mountain babyboot orchid | Lepanthes eltoroensis Stimson | LEEL2 |
| lycaste | Lycaste Lindl. | LYCAS |
| macradenia | Macradenia R. Br. | MACRA |
| Malaxis brachypoda | Malaxis monophyllos (L.) Sw. ssp. brachypoda (Gray) A.& D. L?ve | MAMOB2 |
| Malaxis brachypoda | Malaxis monophyllos (L.) Sw. var. brachypoda (Gray) F. Morris & Eames | MAMOB |
| Malaxis diphyllos | Malaxis monophyllos (L.) Sw. var. diphyllos (Cham.) Luer | MAMOD |
| Malaxis paludosa | Hammarbya paludosa (L.) Kuntze | HAPA11 |
| Malaxis porphyrea | Microstylis porphyrea Ridley | MIPO8 |
| Malaxis soulei | Malaxis macrostachya auct. non (Lex.) Kuntze [misapplied] | MAMA13 |
| Malaxis spicata | Malaxis floridana (Chapman) Kuntze | MAFL7 |
| Malaxis unifolia | Microstylis unifolia (Michx.) B.S.P. | MIUN4 |
| Malaysian orchid | Scaphyglottis modesta (Reichenb. f.) Schlechter | SCMO3 |
| manyflower grasspink | Calopogon multiflorus Lindl. | CAMU10 |
| marsh lady's tresses | Spiranthes odorata (Nutt.) Lindl. | SPOD |
| marsh orchid | Epipactis palustris (L.) Crantz [excluded] | EPPA8 |
| masdevallia | Masdevallia Ruiz & Pav?n | MASDE |
| Masson's adder's-mouth orchid | Malaxis massonii (Ridley) Kuntze | MAMA36 |
| Maxillaria acutifolia | Maxillaria rufescens auct. non Lindl. [misapplied] | MARU2 |
| Maxillaria coccinea | Ornithidium coccineum (Jacq.) Salisb. | ORCO7 |
| Maxillaria crassifolia | Maxillaria sessilis (Sw.) Fawcett & Rendle | MASE3 |
| Maxillaria parviflora | Maxillaria conferta (Griseb.) C. Schweinf. | MACO9 |
| Maxillaria parviflora | Maxillaria purpurea (Spreng.) Ames & Correll p.p. | MAPU6 |
| Maxillaria parviflora | Ornithidium confertum Griseb. | ORCO8 |
| Mesadenus lucayanus | Mesadenus polyanthus auct. non (Reichenb. f.) Schlechter [misapplied] | MEPO6 |
| Mesadenus lucayanus | Spiranthes lucayana (Britt.) Cogn. | SPLU3 |
| Mesadenus lucayanus | Spiranthes polyantha auct. non Reichenb. f. [misapplied] | SPPO3 |
| Mexican vanilla | Vanilla mexicana P. Mill. | VAME2 |
| Michael's piperia | Piperia michaelii (Greene) Rydb. | PIMI6 |
| Michuacan lady orchid | Stenorrhynchos michuacanum (Llave & Lex.) Schlechter | STMI14 |
| Mirador green ladies'-tresses | Cyclopogon miradorense Schlechter | CYMI7 |
| moccasin flower | Cypripedium acaule Ait. | CYAC3 |
| mona | Domingoa haematochila (Reichenb. f.) Carabia | DOHA2 |
| monk orchid | Oeceoclades Lindl. | OECEO |
| monk orchid | Oeceoclades maculata (Lindl.) Lindl. | OEMA2 |
| moss tufted orchid | Jacquiniella teretifolia (Sw.) Britt. & P. Wilson | JATE |
| moth orchid | Phalaenopsis Blume | PHALA10 |
| mountain babyboot orchid | Lepanthes selenitepala Reichenb. f. | LESE2 |
| mountain lady's slipper | Cypripedium montanum Dougl. ex Lindl. | CYMO2 |
| mountain leafystem orchid | Dichaea latifolia Lindl. | DILA23 |
| mountain Prescott orchid | Prescotia stachyodes (Sw.) Lindl. | PRST2 |
| mountain star orchid | Epidendrum ramosum Jacq. | EPRA |
| narrow helmet orchid | Cranichis tenuis Reichenb. f. [excluded] | CRTE6 |
| narrow-petal rein orchid | Piperia leptopetala Rydb. | PILE3 |
| narrowleaf equallip orchid | Isochilus linearis (Jacq.) R. Br. ex Ait. f. | ISLI2 |
| Navasota lady's tresses | Spiranthes parksii Correll | SPPA5 |
| needleroot airplant orchid | Harrisella porrecta (Reichenb. f.) Fawcett & Rendle | HAPO |
| needleroot bentspur orchid | Campylocentrum filiforme (Sw.) Cogn. ex Kuntze | CAFI10 |
| nidema | Nidema Britt. & Millsp. | NIDEM |
| Nidema ottonis | Epidendrum ottonis Reichenb. f. | EPOT |
| night scented orchid | Epidendrum nocturnum Jacq. | EPNO |
| nodding lady's tresses | Spiranthes cernua (L.) L.C. Rich. | SPCE |
| noddingcaps | Triphora Nutt. | TRIPH |
| northern green orchid | Platanthera aquilonis Sheviak | PLAQ2 |
| northern green orchid | Platanthera hyperborea (L.) Lindl. | PLHY2 |
| northern slender lady's tresses | Spiranthes lacera (Raf.) Raf. | SPLA4 |
| northern slender lady's tresses | Spiranthes lacera (Raf.) Raf. var. gracilis (Bigelow) Luer | SPLAG |
| northern slender lady's tresses | Spiranthes lacera (Raf.) Raf. var. lacera | SPLAL |
| northern twayblade | Listera borealis Morong | LIBO4 |
| northwestern twayblade | Listera caurina Piper | LICA10 |
| nun's-hood orchid | Phaius Lour. | PHAIU |
| nun's-hood orchid | Phaius tancarvilleae (Banks ex L'H?r.) Blume | PHTA2 |
| oblong-leaf star orchid | Epidendrum tridens Poepp. & Endl. | EPTR6 |
| October lady's tresses | Spiranthes ovalis Lindl. | SPOV |
| October lady's tresses | Spiranthes ovalis Lindl. var. erostellata Catling | SPOVE |
| October lady's tresses | Spiranthes ovalis Lindl. var. ovalis | SPOVO |
| odontoglossum | Odontoglossum H.B. | ODONT7 |
| Oeceoclades maculata | Eulophidium maculatum (Lindl.) Pfitzer | EUMA13 |
| Oklahoma grasspink | Calopogon oklahomensis D.H. Goldman | CAOK2 |
| Oncidium altissimum | Oncidium baueri auct. non Lindl. [misapplied] | ONBA2 |
| Oncidium altissimum | Oncidium wydleri Reichenb. f. | ONWY |
| Oncidium lemonianum | Oncidium intermedium Bertero [excluded] | ONIN3 |
| Oncidium meirax | Oncidium alatum Cogn. | ONAL |
| ophrys | Ophrys L. | OPHRY |
| orange-flower star orchid | Epidendrum mutelianum Cogn. | EPMU |
| orchis | Orchis L. | ORCHI2 |
| Pacific coralroot | Corallorhiza mertensiana Bong. | COME17 |
| pale grasspink | Calopogon pallidus Chapman | CAPA4 |
| pale laelia | Laelia rubescens Lindl. | LARU5 |
| palegreen orchid | Platanthera flava (L.) Lindl. | PLFL |
| palegreen orchid | Platanthera flava (L.) Lindl. var. flava | PLFLF |
| palegreen orchid | Platanthera flava (L.) Lindl. var. herbiola (R. Br. ex Ait. f.) Luer | PLFLH |
| palmpolly | Dendrophylax lindenii (Lindl.) Benth. ex Rolfe | DELI8 |
| pansy orchid | Miltonia Lindl. | MILTO |
| pantropical widelip orchid | Liparis elata Lindl. | LIEL2 |
| parasitic lady's tresses | Schiedeella arizonica P.M. Brown | SCAR8 |
| parrotbeak orchid | Dilomilis montana (Sw.) Summerhayes | DIMO5 |
| peacock orchid | Psychilis Raf. | PSYCH2 |
| Pelexia adnata | Spiranthes adnata (Sw.) Benth. ex Fawcett | SPAD |
| phantom orchid | Cephalanthera austiniae (Gray) Heller | CEAU |
| Philippine ground orchid | Spathoglottis plicata Blume | SPPL |
| pinepink | Bletia purpurea (Lam.) DC. | BLPU |
| Piperia elegans ssp. elegans | Habenaria elegans (Lindl.) Boland. | HAEL2 |
| Piperia elegans ssp. elegans | Habenaria elegans (Lindl.) Boland. var. maritima (Greene) Ames | HAELM |
| Piperia elegans ssp. elegans | Habenaria greenei Jepson | HAGR8 |
| Piperia elegans ssp. elegans | Habenaria maritima Greene | HAMA4 |
| Piperia elegans ssp. elegans | Habenaria unalascensis (Spreng.) S. Wats. var. maritima (Greene) Correll | HAUNM |
| Piperia elegans ssp. elegans | Piperia maritima (Greene) Rydb. | PIMA3 |
| Piperia elegans ssp. elegans | Piperia multiflora Rydb. | PIMU5 |
| Piperia elegans ssp. elegans | Platanthera unalascensis (Spreng.) Kurtz ssp. maritima (Greene) de Filipps | PLUNM |
| Piperia elegans ssp. elegans | Platanthera unalascensis (Spreng.) Kurtz var. maritima (Greene) Correll | PLUNM2 |
| Piperia elongata | Habenaria unalascensis (Spreng.) S. Wats. ssp. elata (Jepson) Calder | HAUNE |
| Piperia elongata | Habenaria unalascensis (Spreng.) S. Wats. var. elata (Jepson) Correll | HAUNE2 |
| Piperia elongata | Piperia elegans (Lindl.) Rydb. var. elata (Jepson) Luer | PIELE |
| Piperia elongata | Piperia lancifolia Rydb. | PILA3 |
| Piperia elongata | Piperia longispica Dur. | PILO2 |
| Piperia elongata | Platanthera unalascensis (Spreng.) Kurtz ssp. elata (Jepson) Taylor & MacBryde | PLUNE |
| Piperia michaelii | Habenaria michaelii Greene | HAMI3 |
| Piperia michaelii | Piperia elongata Rydb. ssp. michaelii (Greene) Ackerman | PIELM |
| Piperia unalascensis | Habenaria unalascensis (Spreng.) S. Wats. | HAUN |
| Piperia unalascensis | Platanthera unalascensis (Spreng.) Kurtz | PLUN3 |
| Piperia unalascensis | Spiranthes unalascensis Spreng. | SPUN |
| Platanthera ?andrewsii | Habenaria ?andrewsii M. White | HAAN2 |
| Platanthera ?andrewsii | Habenaria lacera (Michx.) R. Br. var. terrae-novae Fern. | HALAT5 |
| Platanthera ?andrewsii | Platanthera lacera (Michx.) G. Don var. terrae-novae (Fern.) Luer | PLLAT |
| Platanthera ?bicolor | Habenaria bicolor (Raf.) Beckner | HABI |
| Platanthera ?canbyi | Habenaria ?canbyi Ames | HACA7 |
| Platanthera ?canbyi | Platanthera pallida P.M. Brown | PLPA6 |
| Platanthera ?media | Habenaria dilatata (Pursh) Hook. var. media (Rydb.) Hult | HADIM |
| Platanthera ?media | Habenaria media (Rydb.) Niles | HAME2 |
| Platanthera ?media | Limnorchis media Rydb. | LIME4 |
| Platanthera ?media | Platanthera convallariifolia (Fisch.) Lindl. var. dilatatoides Hult | PLCOD2 |
| Platanthera ?media | Platanthera dilatata (Pursh) Lindl. ex Beck var. chlorantha Hult | PLDIC |
| Platanthera aquilonis | Habenaria hyperborea auct. non (L.) R. Br. ex Ait. [misapplied] | HAHY3 |
| Platanthera aquilonis | Platanthera hyperborea auct. non (L.) Lindl. [misapplied] | PLHY9 |
| Platanthera blephariglottis var. blephariglottis | Blephariglotis blephariglottis (Willd.) Rydb. | BLBL2 |
| Platanthera blephariglottis var. blephariglottis | Habenaria blephariglottis (Willd.) Hook. | HABL6 |
| Platanthera blephariglottis var. conspicua | Blephariglotis conspicua (Nash) Small | BLCO |
| Platanthera blephariglottis var. conspicua | Habenaria blephariglottis (Willd.) Hook. var. conspicua (Nash) Ames | HABLC |
| Platanthera brevifolia | Habenaria sparsiflora S. Wats. var. brevifolia (Greene) Correll | HASPB |
| Platanthera brevifolia | Platanthera sparsiflora (S. Wats.) Schlechter var. brevifolia (Greene) Luer | PLSPB |
| Platanthera chapmanii | Blephariglotis chapmanii Small | BLCH2 |
| Platanthera chapmanii | Habenaria ?chapmanii (Small) Ames | HACH4 |
| Platanthera chorisiana | Habenaria chorisiana Cham. | HACH3 |
| Platanthera ciliaris | Blephariglotis ciliaris (L.) Rydb. | BLCI2 |
| Platanthera ciliaris | Habenaria ciliaris (L.) R. Br. ex Ait. f. | HACI7 |
| Platanthera clavellata | Gymnadeniopsis clavellata (Michx.) Rydb. | GYCL |
| Platanthera clavellata | Habenaria clavellata (Michx.) Spreng. | HACL3 |
| Platanthera clavellata | Habenaria clavellata (Michx.) Spreng. var. ophioglossoides Fern. | HACLO |
| Platanthera clavellata | Habenaria clavellata (Michx.) Spreng. var. wrightii Olive | HACLW |
| Platanthera cristata | Blephariglotis cristata (Michx.) Raf. | BLCR2 |
| Platanthera cristata | Habenaria cristata (Michx.) R. Br. ex Ait. f. | HACR7 |
| Platanthera dilatata var. albiflora | Habenaria dilatata (Pursh) Hook. var. albiflora (Cham.) Correll | HADIA2 |
| Platanthera dilatata var. albiflora | Limnorchis dilatata (Pursh) Rydb. ssp. albiflora (Cham.) A. L?ve & Simon | LIDIA |
| Platanthera dilatata var. dilatata | Habenaria dilatata (Pursh) Hook. | HADI7 |
| Platanthera dilatata var. dilatata | Limnorchis dilatata (Pursh) Rydb. | LIDI5 |
| Platanthera dilatata var. dilatata | Platanthera dilatata (Pursh) Lindl. ex Beck var. angustifolia Hook. | PLDIA2 |
| Platanthera dilatata var. leucostachys | Habenaria dilatata (Pursh) Hook. var. leucostachys (Lindl.) Ames | HADIL |
| Platanthera dilatata var. leucostachys | Habenaria leucostachys (Lindl.) S. Wats. | HALE5 |
| Platanthera dilatata var. leucostachys | Limnorchis graminifolia Rydb. | LIGR11 |
| Platanthera dilatata var. leucostachys | Platanthera leucostachys Lindl. | PLLE5 |
| Platanthera flava var. flava | Habenaria flava (L.) R. Br. | HAFL6 |
| Platanthera flava var. flava | Habenaria scutellata (Nutt.) F. Morris | HASC2 |
| Platanthera flava var. flava | Perularia bidentata (Ell.) Small | PEBI3 |
| Platanthera flava var. flava | Perularia flava (L.) Farw. | PEFL13 |
| Platanthera flava var. flava | Perularia scutellata (Nutt.) Small | PESC7 |
| Platanthera flava var. herbiola | Habenaria flava (L.) R. Br. var. herbiola (R. Br. ex Ait. f.) Ames & Correll | HAFLH |
| Platanthera flava var. herbiola | Habenaria flava (L.) R. Br. var. virescens sensu Fern., non Orchis virescens Muhl. ex Willd. | HAFLV |
| Platanthera gracilis | Habenaria sparsiflora S. Wats. var. laxiflora (Rydb.) Correll | HASPL2 |
| Platanthera gracilis | Platanthera hyperborea (L.) Lindl. var. gracilis (Lindl.) Luer | PLHYG |
| Platanthera grandiflora | Blephariglotis grandiflora (Bigelow) Rydb. | BLGR |
| Platanthera grandiflora | Habenaria fimbriata (Ait.) R. Br. ex Ait. f. | HAFI2 |
| Platanthera grandiflora | Habenaria grandiflora (Bigelow) Torr. | HAGR9 |
| Platanthera grandiflora | Habenaria psycodes (L.) Spreng. var. grandiflora (Bigelow) Gray | HAPSG |
| Platanthera holochila | Habenaria holochila Hbd. | HAHO3 |
| Platanthera hookeri | Habenaria hookeri Torr. ex Gray | HAHO2 |
| Platanthera hookeri | Habenaria hookeri Torr. ex Gray var. abbreviata Fern. | HAHOA |
| Platanthera hookeri | Lysias hookeriana (Torr. ex Gray) Rydb. | LYHO |
| Platanthera huronensis | Habenaria huronensis (Nutt.) Spreng. | HAHU |
| Platanthera huronensis | Habenaria hyperborea (L.) R. Br. ex Ait. f. var. huronensis (Nutt.) Farw. | HAHYH |
| Platanthera huronensis | Platanthera hyperborea (L.) Lindl. var. huronensis (Nutt.) Luer | PLHYH |
| Platanthera huronensis | Platanthera hyperborea (L.) Lindl. var. major Lange | PLHYM |
| Platanthera hyperborea | Platanthera hyperborea (L.) Lindl. var. hyperborea (L.) Lindl. [superfluous autonym] | PLHYH2 |
| Platanthera hyperborea var. viridiflora | Habenaria hyperborea (L.) R. Br. ex Ait. f. var. viridiflora (Cham.) Welsh | HAHYV |
| Platanthera hyperborea var. viridiflora | Limnorchis viridiflora (Cham.) Rydb. | LIVI5 |
| Platanthera hyperborea var. viridiflora | Platanthera convallariifolia (Fisch.) Lindl. | PLCO15 |
| Platanthera integra | Gymnadeniopsis integra (Nutt.) Rydb. | GYIN2 |
| Platanthera integra | Habenaria integra (Nutt.) Spreng. | HAIN4 |
| Platanthera integrilabia | Habenaria blephariglottis (Willd.) Hook. var. integrilabia Correll | HABLI |
| Platanthera integrilabia | Habenaria correlliana Cronq. | HACO10 |
| Platanthera integrilabia | Habenaria correllii Cronq. [orthographic variant] | HACO8 |
| Platanthera lacera | Blephariglotis lacera (Michx.) Farw. | BLLA2 |
| Platanthera lacera | Habenaria lacera (Michx.) R. Br. | HALA6 |
| Platanthera leucophaea | Blephariglotis leucophaea (Nutt.) Farw. | BLLE |
| Platanthera leucophaea | Habenaria leucophaea (Nutt.) Gray | HALE3 |
| Platanthera limosa | Habenaria limosa (Lindl.) Hemsl. | HALI6 |
| Platanthera limosa | Limnorchis thurberi (Gray) Rydb. | LITH |
| Platanthera macrophylla | Habenaria macrophylla Goldie | HAMA5 |
| Platanthera macrophylla | Habenaria orbiculata (Pursh) Torr. var. macrophylla (Goldie) Boivin | HAORM |
| Platanthera macrophylla | Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer | PLORM |
| Platanthera nivea | Gymnadeniopsis nivea (Nutt.) Rydb. | GYNI2 |
| Platanthera nivea | Habenaria nivea (Nutt.) Spreng. | HANI2 |
| Platanthera obtusata ssp. obtusata | Habenaria obtusata (Banks ex Pursh) Richards. | HAOB2 |
| Platanthera obtusata ssp. obtusata | Habenaria obtusata (Banks ex Pursh) Richards. var. collectanea Fern. | HAOBC |
| Platanthera obtusata ssp. obtusata | Lysiella obtusata (Banks ex Pursh) Rydb. | LYOB2 |
| Platanthera obtusata ssp. oligantha | Platanthera oligantha Turcz. | PLOL3 |
| Platanthera orbiculata | Habenaria orbiculata (Pursh) Torr. | HAOR2 |
| Platanthera orbiculata | Habenaria orbiculata (Pursh) Torr. var. lehorsii Fern. | HAORL |
| Platanthera orbiculata | Habenaria orbiculata (Pursh) Torr. var. menziesii (Lindl.) Fern. | HAORM2 |
| Platanthera orbiculata | Lysias orbiculata (Pursh) Rydb. | LYOR |
| Platanthera peramoena | Blephariglotis peramoena (Gray) Rydb. | BLPE |
| Platanthera peramoena | Habenaria peramoena Gray | HAPE4 |
| Platanthera praeclara | Habenaria leucophaea (Nutt.) Gray var. praeclara (Sheviak & Bowles) Cronq. | HALEP |
| Platanthera psycodes | Blephariglotis psycodes (L.) Rydb. | BLPS |
| Platanthera psycodes | Habenaria psycodes (L.) Spreng. | HAPS2 |
| Platanthera purpurascens | Limnorchis purpurascens Rydb. | LIPU10 |
| Platanthera purpurascens | Platanthera hyperborea (L.) Lindl. var. purpurascens (Rydb.) Luer | PLHYP |
| Platanthera sparsiflora var. ensifolia | Limnorchis ensifolia Rydb. | LIEN2 |
| Platanthera sparsiflora var. sparsiflora | Habenaria sparsiflora S. Wats. | HASP5 |
| Platanthera sparsiflora var. sparsiflora | Limnorchis sparsiflora (S. Wats.) Rydb. | LISP6 |
| Platanthera stricta | Habenaria saccata Greene | HASA |
| Platanthera stricta | Habenaria stricta (Lindl.) Rydb. | HAST5 |
| Platanthera stricta | Limnorchis saccata (Greene) A. L?ve & Simon | LISA5 |
| Platanthera stricta | Limnorchis stricta (Lindl.) Rydb. | LIST8 |
| Platanthera stricta | Platanthera dilatata (Pursh) Lindl. ex Beck var. gracilis Ledeb. | PLDIG |
| Platanthera stricta | Platanthera saccata (Greene) Hult | PLSA6 |
| Platanthera tipuloides var. behringiana | Habenaria behringiana (Rydb.) Ames | HABE4 |
| Platanthera zothecina | Habenaria zothecina Higgins & Welsh | HAZO |
| Platanthera zothecina | Limnorchis zothecina (Higgins & Welsh) W.A. Weber | LIZO |
| platythelys | Platythelys Garay | PLATY7 |
| Platythelys querceticola | Erythrodes querceticola (Lindl.) Ames | ERQU2 |
| Platythelys querceticola | Physurus querceticola Lindl. | PHQU4 |
| Platythelys sagraeanus | Physurus sagraeanus A. Rich. | PHSA8 |
| Pleurothallis aristata | Pleurothallis urbaniana Reichenb. f. | PLUR |
| Pleurothallis domingensis | Pleurothallis crassipes sensu Britt. & P. Wilson, non Lindl. | PLCR2 |
| Pleurothallis pubescens | Pleurothallis coriacea Bello | PLCO5 |
| Pleurothallis racemiflora | Pleurothallis ghiesbreghtiana A. Rich. & Gal. | PLGH |
| Pleurothallis racemiflora | Pleurothallis longissima Lindl. | PLLO |
| pogonia | Pogonia Juss. | POGON |
| Pogonia ophioglossoides | Pogonia ophioglossoides (L.) Ker-Gawl. var. brachypogon Fern. | POOPB |
| Poit's vanilla | Vanilla poitaei Reichenb. f. | VAPO |
| Polystachya concreta | Polystachya extinctoria Reichenb. f. | POEX3 |
| Polystachya concreta | Polystachya flavescens (Lindl.) J.J. Sm. | POFL6 |
| Polystachya concreta | Polystachya luteola (Sw.) Hook. | POLU3 |
| Polystachya concreta | Polystachya minuta (Aubl.) Britt. | POMI9 |
| Polystachya foliosa | Polystachya cerea Lindl. | POCE2 |
| Polystachya foliosa | Polystachya minor Fawcett & Rendle | POMI16 |
| Ponthieva brittoniae | Ponthieva racemosa (Walt.) C. Mohr var. brittoniae (Ames) Luer | PORAB |
| Ponthieva racemosa | Arethusa racemosa Walt. | ARRA3 |
| prairie white fringed orchid | Platanthera leucophaea (Nutt.) Lindl. | PLLE2 |
| Prescotia oligantha | Cranichis oligantha Sw. | CROL |
| Prescotia stachyodes | Cranichis stachyodes Sw. | CRST8 |
| Prescott orchid | Prescotia Lindl. | PRESC |
| Prosthechea boothiana var. erythronioides | Encyclia boothiana (Lindl.) Dressler var. erythronioides (Small) Luer | ENBOE2 |
| Prosthechea boothiana var. erythronioides | Encyclia boothiana auct. non (Lindl.) Dressler [misapplied] | ENBO |
| Prosthechea boothiana var. erythronioides | Epicladium boothianum auct. non (Lindl.) Small [misapplied] | EPBO3 |
| Prosthechea boothiana var. erythronioides | Epidendrum erythronioides Small | EPER |
| Prosthechea cochleata var. cochleata | Anacheilium cochleatum (L.) Hoffmgg. | ANCO10 |
| Prosthechea cochleata var. cochleata | Encyclia cochleata (L.) Dressler | ENCO3 |
| Prosthechea cochleata var. cochleata | Epidendrum cochleatum L. | EPCO3 |
| Prosthechea cochleata var. triandra | Anacheilium cochleatum (L.) Hoffmgg. var. triandrum (Ames) Sauleda, Wunderlin & B.F. Hansen | ANCOT |
| Prosthechea cochleata var. triandra | Encyclia cochleata (L.) Dressler ssp. triandra (Ames) H?gsater | ENCOT2 |
| Prosthechea cochleata var. triandra | Encyclia cochleata (L.) Dressler var. triandra (Ames) Dressler | ENCOT |
| Prosthechea cochleata var. triandra | Epidendrum cochleatum L. var. triandrum Ames | EPCOT |
| Prosthechea pygmaea | Coelia triptera auct. non (Sm.) G. Don ex Steud. [misapplied] | COTR6 |
| Prosthechea pygmaea | Encyclia pygmaea (Hook.) Dressler | ENPY |
| Prosthechea pygmaea | Epidendrum pygmaeum Hook. | EPPY2 |
| Prosthechea pygmaea | Hormidium pygmaeum (Hook.) Benth. & Hook. f. | HOPY2 |
| Prosthechea pygmaea | Hormidium tripterum (Brongn.) Cogn. | HOTR3 |
| psilochilus | Psilochilus Barb. Rodr. | PSILO5 |
| Psilochilus macrophyllus | Pogonia macrophylla Lindl. | POMA13 |
| Psychilis kraenzlinii | Encyclia kraenzlinii (Bello) Ackerman | ENKR |
| Psychilis kraenzlinii | Epidendrum kraenzlinii Bello | EPKR2 |
| Psychilis krugii | Encyclia krugii (Bello) Britt. & P. Wilson | ENKR2 |
| Psychilis krugii | Epidendrum krugii Bello | EPKR |
| pteroglossaspis | Pteroglossaspis Rehb. f. | PTERO7 |
| Pteroglossaspis ecristata | Eulophia ecristata (Fern.) Ames | EUEC |
| Pteroglossaspis ecristata | Triorchos ecristata (Fern.) Small | TREC |
| Puerto Rico babyboot orchid | Lepanthes veleziana Stimson | LEVE |
| Puerto Rico babyboot orchid | Lepanthes veleziana Stimson var. retusicolumna Stimson | LEVER |
| Puerto Rico babyboot orchid | Lepanthes veleziana Stimson var. veleziana | LEVEV |
| Puerto Rico helmet orchid | Cranichis ricartii Ackerman | CRRI4 |
| Puerto Rico smoothlip orchid | Leochilus puertoricensis M. Chase | LEPU5 |
| purple fringeless orchid | Platanthera peramoena (Gray) Gray | PLPE |
| purple tiger orchid | Maxillaria parviflora (Poepp. & Endl.) Garay | MAPA22 |
| purple-petal bog orchid | Platanthera purpurascens (Rydb.) Sheviak & Jennings | PLPU7 |
| pygmy bentspur orchid | Campylocentrum pygmaeum Cogn. | CAPY4 |
| pygmy leach orchid | Stelis pygmaea Cogn. | STPY2 |
| raggedlip orchid | Psilochilus macrophyllus (Lindl.) Ames | PSMA8 |
| ram's head lady's slipper | Cypripedium arietinum Ait. f. | CYAR5 |
| rat-tail orchid | Bulbophyllum pachyrrachis (A. Rich.) Griseb. | BUPA2 |
| rattlesnake plantain | Goodyera R. Br. ex Ait. f. | GOODY |
| reclusive lady's tresses | Spiranthes delitescens Sheviak | SPDE6 |
| redblotch tufted orchid | Jacquiniella globosa (Jacq.) Schlechter | JAGL |
| rein orchid | Piperia Rydb. | PIPER2 |
| renanthera | Renanthera Lour. | RENAN |
| ribbed bonnet orchid | Pleurothallis tricostata Cogn. | PLTR4 |
| rock babyboot orchid | Lepanthes rupestris Stimson | LERU2 |
| rosebud orchid | Cleistes divaricata (L.) Ames | CLDI |
| rosebud orchid | Cleistes L.C. Rich. ex Lindl. | CLEIS |
| round-leaf star orchid | Epidendrum carpophorum B. Rodrigues | EPCA6 |
| roundleaf orchid | Amerorchis rotundifolia (Banks ex Pursh) Hult | AMRO |
| royal adder's-mouth orchid | Malaxis major (Reichenb. f.) L?on ex A.D. Hawkes | MAMA22 |
| royal helleborine | Epipactis atrorubens (O. Hoffmann) Bess. | EPAT |
| royal peacock orchid | Psychilis monensis Sauleda | PSMO3 |
| royal rein orchid | Piperia transversa Suksdorf | PITR3 |
| royal star orchid | Encyclia isochila (Reichenb. f.) D. Dod | ENIS |
| rufous butterfly orchid | Encyclia rufa (Lindl.) Britt. & Millsp. | ENRU |
| rufous tiger orchid | Maxillaria acutifolia Lindl. | MAAC5 |
| Saunders's widelip orchid | Liparis saundersiana Reichenb. f. | LISA2 |
| scaphyglottis | Scaphyglottis Poepp. & Endl. | SCAPH |
| Scaphyglottis modesta | Tetragamestus modestus Reichenb. f. | TEMO2 |
| scarlet lady's tresses | Dichromanthus cinnabarinus (Llave & Lex.) Garay | DICI3 |
| scentbottle | Platanthera dilatata (Pursh) Lindl. ex Beck | PLDI3 |
| scentbottle | Platanthera dilatata (Pursh) Lindl. ex Beck var. albiflora (Cham.) Ledeb. | PLDIA |
| scentbottle | Platanthera dilatata (Pursh) Lindl. ex Beck var. dilatata | PLDID |
| scentless vanilla | Vanilla inodora Schiede | VAIN |
| Schiedeella arizonica | Schiedeella fauci-sanguinea auct. non (D. Dod) Burns-Balogh [misapplied] | SCFA4 |
| Schiedeella arizonica | Schiedeella parasitica auct. non (A. Rich. & Gal.) Schlechter [misapplied] | SCPA28 |
| Schiedeella arizonica | Spiranthes parasitica auct. non A. Rich. & Gal. [misapplied] | SPPA4 |
| serpentine wallflower orchid | Tetramicra canaliculata (Aubl.) Urban | TECA4 |
| shadow witch | Ponthieva R. Br. ex Ait. f. | PONTH |
| Sherring's cup orchid | Brachionidium sherringii Rolfe | BRSH3 |
| shining lady's tresses | Spiranthes lucida (H.H. Eat.) Ames | SPLU2 |
| shortflowered bog orchid | Platanthera brevifolia (Greene) Kranzlin | PLBR3 |
| showy lady's slipper | Cypripedium reginae Walt. | CYRE6 |
| showy orchid | Galearis spectabilis (L.) Raf. | GASP5 |
| Sierra bog orchid | Platanthera dilatata (Pursh) Lindl. ex Beck var. leucostachys (Lindl.) Luer | PLDIL |
| Simpson's grasspink | Calopogon tuberosus (L.) B.S.P. var. simpsonii (Chapman) Magrath | CATUS |
| slender bog orchid | Platanthera stricta Lindl. | PLST4 |
| slender pinepink | Bletia florida (Salisb.) R. Br. ex Ait. f. | BLFL |
| slender-spire orchid | Piperia unalascensis (Spreng.) Rydb. | PIUN3 |
| small green wood orchid | Platanthera clavellata (Michx.) Luer | PLCL |
| small Prescott orchid | Prescotia oligantha (Sw.) Lindl. | PROL |
| small spreading pogonia | Cleistes bifaria (Fern.) Catling & Gregg | CLBI3 |
| small whorled pogonia | Isotria medeoloides (Pursh) Raf. | ISME2 |
| smooth shadow witch | Ponthieva ventricosa (Griseb.) Fawcett & Rendle | POVE2 |
| snail orchid | Comparettia falcata Poepp. & Endl. | COFA2 |
| snakemouth orchid | Pogonia ophioglossoides (L.) Ker-Gawl. | POOP |
| snowy orchid | Platanthera nivea (Nutt.) Luer | PLNI |
| sobralia | Sobralia Ruiz & Pav?n | SOBRA |
| soldier's orchid | Zeuxine strateumatica (L.) Schlechter | ZEST |
| South American bonnet orchid | Pleurothallis obovata (Lindl.) Lindl. | PLOB4 |
| southern lady's tresses | Spiranthes torta (Thunb.) Garay & Sweet | SPTO5 |
| southern twayblade | Listera australis Lindl. | LIAU3 |
| sparrowegg lady's slipper | Cypripedium passerinum Richards. | CYPA5 |
| sparse-flowered bog orchid | Platanthera sparsiflora (S. Wats.) Schlechter | PLSP2 |
| sparse-flowered bog orchid | Platanthera sparsiflora (S. Wats.) Schlechter var. ensifolia (Rydb.) Luer | PLSPE |
| sparse-flowered bog orchid | Platanthera sparsiflora (S. Wats.) Schlechter var. sparsiflora | PLSPS |
| spiked crested coralroot | Hexalectris spicata (Walt.) Barnh. | HESP3 |
| spiked crested coralroot | Hexalectris spicata (Walt.) Barnh. var. arizonica (S. Wats.) Catling & Engel | HESPA |
| spiked crested coralroot | Hexalectris spicata (Walt.) Barnh. var. spicata | HESPS3 |
| Spiranthes ?intermedia | Ibidium ?intermedium (Ames) House | IBIN |
| Spiranthes bicolor | Beadlea bicolor (Ker-Gawl.) Garay [excluded] | BEBI |
| Spiranthes brevilabris | Spiranthes brevilabris Lindl. var. brevilabris Lindl. [superfluous autonym] | SPBRB |
| Spiranthes brevilabris | Spiranthes gracilis (Bigelow) Beck var. brevilabris (Lindl.) Correll | SPGRB |
| Spiranthes casei var. casei | Spiranthes ?intermedia auct. non Ames [misapplied] | SPIN11 |
| Spiranthes cernua | Ibidium cernuum (L.) House | IBCE |
| Spiranthes cernua | Spiranthes cernua (L.) L.C. Rich. var. incurva Jennings | SPCEI |
| Spiranthes diluvialis | Spiranthes romanzoffiana Cham. var. diluvialis (Sheviak) Welsh | SPROD |
| Spiranthes floridana | Ibidium floridanum Wherry | IBFL |
| Spiranthes floridana | Spiranthes brevilabris Lindl. var. floridana (Wherry) Luer | SPBRF |
| Spiranthes floridana | Spiranthes gracilis (Bigelow) Beck var. floridana (Wherry) Correll | SPGRF |
| Spiranthes lacera var. gracilis | Ibidium beckii (Lindl.) House | IBBE |
| Spiranthes lacera var. gracilis | Ibidium gracile (Bigelow) House | IBGR |
| Spiranthes lacera var. gracilis | Spiranthes beckii Lindl. | SPBE3 |
| Spiranthes lacera var. gracilis | Spiranthes gracilis (Bigelow) Beck | SPGR8 |
| Spiranthes laciniata | Ibidium laciniatum (Small) House | IBLA |
| Spiranthes lanceolata var. luteoalba | Sacoila lanceolata (Aubl.) Garay var. luteoalba (Reichenb. f.) Sauleda, Wunderlin & B.F. Hansen [excluded] | SALAL8 |
| Spiranthes longilabris | Ibidium longilabre (Lindl.) House | IBLO |
| Spiranthes lucida | Ibidium plantagineum (Raf.) House | IBPL |
| Spiranthes ochroleuca | Spiranthes ?steigeri Correll | SPST2 |
| Spiranthes ochroleuca | Spiranthes cernua (L.) L.C. Rich. var. ochroleuca (Rydb.) Ames | SPCEO |
| Spiranthes odorata | Spiranthes cernua (L.) L.C. Rich. var. odorata (Nutt.) Correll | SPCEO2 |
| Spiranthes ovalis var. ovalis | Ibidium ovale (Lindl.) House | IBOV |
| Spiranthes porrifolia | Spiranthes romanzoffiana Cham. var. porrifolia (Lindl.) Ames & Correll | SPROP |
| Spiranthes praecox | Ibidium praecox (Walt.) House | IBPR |
| Spiranthes romanzoffiana | Ibidium strictum (Rydb.) House | IBST |
| Spiranthes romanzoffiana | Spiranthes stricta Rydb. | SPST6 |
| Spiranthes torta | Ibidium tortile (Sw.) House | IBTO |
| Spiranthes torta | Spiranthes tortilis (Sw.) L.C. Rich. | SPTO3 |
| Spiranthes tuberosa | Spiranthes grayi Ames | SPGR6 |
| Spiranthes tuberosa | Spiranthes tuberosa Raf. var. grayi (Ames) Fern. | SPTUG |
| Spiranthes vernalis | Ibidium vernale (Engelm. & Gray) House | IBVE |
| Spiranthes vernalis | Spiranthes sinensis (Pers.) Ames | SPSI7 |
| spotted lady's slipper | Cypripedium guttatum Sw. | CYGU |
| spotted lady's slipper | Cypripedium yatabeanum Makino | CYYA |
| spring coralroot | Corallorhiza wisteriana Conrad | COWI5 |
| spring lady's tresses | Spiranthes vernalis Engelm. & Gray | SPVE |
| stanhopea | Stanhopea J. Frost ex Hook. | STANH2 |
| star orchid | Epidendrum L. | EPIDE |
| Stenorrhynchos lanceolatum var. lanceolatum | Sacoila lanceolata (Aubl.) Garay | SALA13 |
| Stenorrhynchos lanceolatum var. lanceolatum | Spiranthes lanceolata (Aubl.) L?on | SPLA5 |
| Stenorrhynchos lanceolatum var. lanceolatum | Spiranthes orchioides (Sw.) A. Rich. | SPOR2 |
| Stenorrhynchos lanceolatum var. lanceolatum | Stenorrhynchos orchioides (Sw.) Lindl. | STOR3 |
| Stenorrhynchos lanceolatum var. paludicola | Sacoila lanceolata (Aubl.) Garay var. paludicola (Luer) Sauleda, Wunderlin & B.F. Hansen | SALAP2 |
| Stenorrhynchos lanceolatum var. paludicola | Spiranthes lanceolata (Aubl.) L?on var. paludicola Luer | SPLAP |
| Stenorrhynchos michuacanum | Spiranthes michuacana (Llave & Lex.) Hemsl. | SPMI2 |
| Stenorrhynchos michuacanum | Stenorrhynchos michuacanus (Llave & Lex.) Schlechter [orthographic variant] | STMI5 |
| Stenorrhynchos speciosum | Spiranthes speciosa (Jacq.) A. Rich. | SPSP3 |
| Stenorrhynchos speciosum | Stenorrhynchos speciosus (Jacq.) L.C. Rich. ex Spreng. [orthographic variant] | STSP10 |
| Stenorrhynchos squamulosum | Sacolia squamulosa (Kunth) Garay | SASQ3 |
| stiff flower star orchid | Epidendrum rigidum Jacq. | EPRI2 |
| stream orchid | Epipactis gigantea Dougl. ex Hook. | EPGI |
| summer coralroot | Corallorhiza maculata (Raf.) Raf. | COMA25 |
| summer coralroot | Corallorhiza maculata (Raf.) Raf. var. maculata | COMAM7 |
| summer coralroot | Corallorhiza maculata (Raf.) Raf. var. occidentalis (Lindl.) Ames | COMAO5 |
| Swartz's leafystem orchid | Dichaea pendula (Aubl.) Cogn. | DIPE9 |
| tall Alaskan green orchid | Platanthera hyperborea (L.) Lindl. var. viridiflora (Cham.) Luer | PLHYV |
| tall ladies'-tresses | Cyclopogon elatus (Sw.) Schlechter | CYEL6 |
| Tampa butterfly orchid | Encyclia tampensis (Lindl.) Small | ENTA |
| terrestrial cowhorn orchid | Cyrtopodium polyphyllum (Vell.) Pabst ex Barrios | CYPO10 |
| Tetramicra canaliculata | Tetramicra elegans (Hamilton) Cogn. | TEEL2 |
| Texas crested coralroot | Hexalectris warnockii Ames & Correll | HEWA |
| Texas lady's tresses | Spiranthes brevilabris Lindl. | SPBR |
| threebirds | Triphora trianthophora (Sw.) Rydb. | TRTR3 |
| Thurber's bog orchid | Platanthera limosa Lindl. | PLLI3 |
| tiger orchid | Elleanthus K. Presl | ELLEA |
| tiger orchid | Maxillaria Ruiz & Pav?n | MAXIL |
| tiny orchid | Lepanthopsis melanantha (Reichenb. f.) Ames | LEME |
| tipularia | Tipularia Nutt. | TIPUL |
| Tipularia discolor | Tipularia unifolia B.S.P. | TIUN2 |
| Tolumnia bahamensis | Oncidium bahamense Nash ex Britt. & Millsp. | ONBA |
| Tolumnia prionochila | Oncidium prionochilum Kraenzlin | ONPR |
| Tolumnia variegata | Oncidium leiboldii auct. non Reichenb. f. [misapplied] | ONLE |
| Tolumnia variegata | Oncidium variegatum (Sw.) Sw. | ONVA |
| Tolumnia variegata | Tolumnia leiboldii auct. non (Reichenb. f.) G.J. Braem [misapplied] | TOLE3 |
| toothpetal bog orchid | Habenaria odontopetala Reichenb. f. | HAOD |
| Trichocentrum maculatum | Lophiaris maculata (Aubl.) Ackerman | LOMA17 |
| Trichocentrum maculatum | Oncidium luridum auct. non Lindl. [misapplied] | ONLU |
| Trichocentrum maculatum | Oncidium maculatum (Aubl.) Ackerman | ONMA |
| Trichocentrum maculatum | Oncidium undulatum (Sw.) Salisb. | ONUN |
| Trichosalpinx dura | Pleurothallis foliata Griseb. | PLFO3 |
| Triphora amazonica | Triphora latifolia Luer f. | TRLA17 |
| Triphora gentianoides | Triphora cubensis (Reichenb. f.) Ames | TRCU2 |
| Triphora rickettii | Triphora yucatanensis auct. non Ames [misapplied] | TRYU |
| Triphora trianthophora | Triphora trianthophora (Sw.) Rydb. var. schaffneri Camp | TRTRS |
| tropical bog orchid | Habenaria monorrhiza (Sw.) Reichenb. f. | HAMO2 |
| tropical dancing-lady orchid | Tolumnia prionochila (Kraenzlin) G.J. Braem | TOPR3 |
| tropical govenia | Govenia floridana P.M. Brown | GOFL2 |
| tropical ladies'-tresses | Hapalorchis lineatus (Lindl.) Schlechter | HALI7 |
| tropical widelip orchid | Liparis vexillifera (Llave & Lex.) Cogn. | LIVE3 |
| tropidia | Tropidia Lindl. | TROPI2 |
| tuberous grasspink | Calopogon tuberosus (L.) B.S.P. | CATU5 |
| tuberous grasspink | Calopogon tuberosus (L.) B.S.P. var. tuberosus | CATUT |
| tufted orchid | Jacquiniella Schlechter | JACQU3 |
| twayblade | Listera R. Br. ex Ait. f. | LISTE |
| umbrella star orchid | Epidendrum jamaicense Lindl. | EPJA |
| urn orchid | Bletilla striata (Thunb.) Reichenb. f. | BLST |
| Ute lady's tresses | Spiranthes diluvialis Sheviak | SPDI6 |
| vanda | Vanda W. Jones ex R. Br. | VANDA |
| vanilla | Vanilla P. Mill. | VANIL |
| vanilla | Vanilla planifolia G. Jackson | VAPL2 |
| Vanilla barbellata | Vanilla articulata Northrop | VAAR5 |
| Vanilla dilloniana | Vanilla eggersii auct. non Rolfe [misapplied] | VAEG |
| Vanilla mexicana | Vanilla vanilla (L.) Britt. | VAVA3 |
| Vanilla planifolia | Vanilla fragrans (Salisb.) Ames | VAFR |
| variegated orchid | Tolumnia bahamensis (Nash ex Britt. & Millsp.) G.J. Braem | TOBA2 |
| Venus's slipper | Paphiopedilum Pfitzer | PAPHI |
| violet orchid | Ionopsis Kunth | IONOP2 |
| Vreeland's coralroot | Corallorhiza striata Lindl. var. vreelandii (Rydb.) L.O. Williams | COSTV2 |
| wallflower orchid | Tetramicra Lindl. | TETRA8 |
| waterspider bog orchid | Habenaria repens Nutt. | HARE |
| waxy bonnet orchid | Pleurothallis pruinosa Lindl. | PLPR2 |
| Wendt's adder's-mouth orchid | Malaxis wendtii Salazar | MAWE |
| West Indian leach orchid | Stelis perpusilliflora Cogn. | STPE |
| West Indian vanilla | Vanilla pompona Schiede | VAPO2 |
| western rattlesnake plantain | Goodyera oblongifolia Raf. | GOOB2 |
| white adder's-mouth orchid | Malaxis brachypoda (Gray) Fern. | MABR5 |
| white fringed orchid | Platanthera blephariglottis (Willd.) Lindl. | PLBL |
| white fringed orchid | Platanthera blephariglottis (Willd.) Lindl. var. blephariglottis | PLBLB |
| white fringed orchid | Platanthera blephariglottis (Willd.) Lindl. var. conspicua (Nash) Luer | PLBLC |
| white fringeless orchid | Platanthera integrilabia (Correll) Luer | PLIN6 |
| white lady's slipper | Cypripedium candidum Muhl. ex Willd. | CYCA5 |
| whiteflower rein orchid | Piperia candida R. Morgan & Ackerman | PICA13 |
| widelip orchid | Liparis L.C. Rich. | LIPAR |
| wild coco | Eulophia alta (L.) Fawcett & Rendle | EUAL6 |
| wild coco | Eulophia R. Br. ex Lindl. | EULOP |
| Wilson's bonnet orchid | Pleurothallis wilsonii Lindl. | PLWI |
| winged bog orchid | Habenaria alata Hook. | HAAL |
| winged-lady orchid | Oncidium meirax Reichenb. f. | ONME |
| Woodbury's babyboot orchid | Lepanthes woodburyana Stimson | LEWO |
| woodland bog orchid | Habenaria eustachya Reichenb. f. | HAEU |
| woodland tuftedorchid | Epidendrum miserrimum Reichenb. f. | EPMI4 |
| wormvine orchid | Vanilla barbellata Reichenb. f. | VABA |
| wullschlaegelia | Wullschlaegelia Reichenb. f. | WULLS |
| Wydler's dancing-lady orchid | Oncidium altissimum (Jacq.) Sw. | ONAL2 |
| Yadon's piperia | Piperia yadonii R. Morgan & Ackerman | PIYA |
| yellow coralroot | Corallorhiza trifida Chatelain | COTR18 |
| yellow fringed orchid | Platanthera ciliaris (L.) Lindl. | PLCI2 |
| yellow fringeless orchid | Platanthera integra (Nutt.) Gray ex Beck | PLIN5 |
| yellow nodding lady's tresses | Spiranthes ochroleuca (Rydb.) Rydb. | SPOC |
| yellow widelip orchid | Liparis loeselii (L.) L.C. Rich. | LILO |
| yellowspike orchid | Polystachya Hook. | POLYS3 |
| young palm orchid | Tropidia polystachya (Sw.) Ames | TRPO5 |
| Yucatan noddingcaps | Triphora rickettii Luer | TRRI4 |
| zeuxine | Zeuxine Lindl. | ZEUXI |