| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| NOCO4 | Nopalea cochenillifera (L.) Salm-Dyck | Opuntia cochenillifera | Cactaceae
|
| NOPU | Normandina pulchella (Borrer) Nyl. | clam lichen | Uncertain Lichen Family
|
| NORMA | Normandina Nyl. | clam lichen | Uncertain Lichen Family
|
| NOAL3 | Norta altissima (L.) Britt. | Sisymbrium altissimum | Brassicaceae
|
| NOIR | Norta irio (L.) Britt. | Sisymbrium irio | Brassicaceae
|
| NOAL2 | Nothocalais alpestris (Gray) Chambers | alpine lake prairie-dandelion | Asteraceae
|
| NOCU | Nothocalais cuspidata (Pursh) Greene | sharppoint prairie-dandelion | Asteraceae
|
| NONI | Nothocalais nigrescens (Henderson) Heller | meadow prairie-dandelion | Asteraceae
|
| NOTR2 | Nothocalais troximoides (Gray) Greene | weevil prairie-dandelion | Asteraceae
|
| NOTHO5 | Nothocalais (Gray) Greene | prairie-dandelion | Asteraceae
|
| NOBRL | Nothocestrum breviflorum Gray var. longipes Hbd. | Nothocestrum breviflorum | Solanaceae
|
| NOBR2 | Nothocestrum breviflorum Gray | smallflower aiea | Solanaceae
|
| NOBRR | Nothocestrum brevifolium Gray var. rupilosum B.C. Stone | Nothocestrum breviflorum | Solanaceae
|
| NOIN5 | Nothocestrum inconcinnum St. John | Nothocestrum peltatum | Solanaceae
|
| NOLA | Nothocestrum latifolium Gray | broadleaf aiea | Solanaceae
|
| NOLOB | Nothocestrum longifolium Gray var. brevifolium Hbd. | Nothocestrum longifolium | Solanaceae
|
| NOLOR | Nothocestrum longifolium Gray var. rufipilosum B.C. Stone | Nothocestrum longifolium | Solanaceae
|
| NOLO | Nothocestrum longifolium Gray | longleaf aiea | Solanaceae
|
| NOPE | Nothocestrum peltatum Skottsberg | Oahu aiea | Solanaceae
|
| NOSU | Nothocestrum subcordatum Mann | Nothocestrum latifolium | Solanaceae
|
| NOTHO3 | Nothocestrum Gray | aiea | Solanaceae
|
| NONE3 | Nothochelone nemorosa (Dougl. ex Lindl.) Straw | woodland beardtongue | Scrophulariaceae
|
| NOTHO4 | Nothochelone (Gray) Straw | nothochelone | Scrophulariaceae
|
| NOOB | Nothofagus obliqua (Birb.) Blume | roble beech | Betulaceae
|
| NOTHO7 | Nothofagus Blume, nom. cons. | southern beech | Betulaceae
|
| NOLA2 | Nothoholcus lanatus (L.) Nash | Holcus lanatus | Poaceae
|
| NOAL | Notholaena aliena Maxon | foreign cloak fern | Pteridaceae
|
| NOAS | Notholaena aschenborniana Klotzsch | scaled cloak fern | Pteridaceae
|
| NOAU | Notholaena aurea (Poir.) Desv. | Cheilanthes bonariensis | Pteridaceae
|
| NOCAC2 | Notholaena californica D.C. Eat. ssp. californica | California cloak fern | Pteridaceae
|
| NOCAL | Notholaena californica D.C. Eat. ssp. leucophylla Windham | California cloak fern | Pteridaceae
|
| NOCAN | Notholaena californica D.C. Eat. ssp. nigrescens Ewan | Notholaena californica ssp. californica | Pteridaceae
|
| NOCA | Notholaena californica D.C. Eat. | California cloak fern | Pteridaceae
|
| NOCAA | Notholaena candida (Mart. & Gal.) Hook. var. accessita Jepson | Notholaena californica ssp. californica | Pteridaceae
|
| NOCAC | Notholaena candida (Mart. & Gal.) Hook. var. copelandii (C.C. Hall) R. Tryon | Notholaena copelandii | Pteridaceae
|
| NOCO2 | Notholaena cochisensis Goodding | Astrolepis cochisensis ssp. cochisensis | Pteridaceae
|
| NOCO5 | Notholaena copelandii C.C. Hall | Copeland's cloak fern | Pteridaceae
|
| NODE | Notholaena dealbata (Pursh) Kunze | Argyrochosma dealbata | Pteridaceae
|
| NOFE | Notholaena fendleri Kunze | Argyrochosma fendleri | Pteridaceae
|
| NOGRG | Notholaena grayi Davenport ssp. grayi | Gray's cloak fern | Pteridaceae
|
| NOGRS | Notholaena grayi Davenport ssp. sonorensis Windham | Sonoran cloak fern | Pteridaceae
|
| NOGR | Notholaena grayi Davenport | Gray's cloak fern | Pteridaceae
|
| NOGR2 | Notholaena greggii (Mett. ex Kuhn) Maxon | Gregg's cloak fern | Pteridaceae
|
| NOIN4 | Notholaena incana K. Presl | Argyrochosma incana | Pteridaceae
|
| NOIN2 | Notholaena integerrima (Hook.) Hevly | Astrolepis integerrima | Pteridaceae
|
| NOJO | Notholaena jonesii Maxon | Argyrochosma jonesii | Pteridaceae
|
| NOLE | Notholaena lemmonii D.C. Eat. | Lemmon's cloak fern | Pteridaceae
|
| NOLIM2 | Notholaena limitanea Maxon ssp. mexicana Maxon | Argyrochosma limitanea ssp. mexicana | Pteridaceae
|
| NOLIM | Notholaena limitanea Maxon var. mexicana (Maxon) Broun | Argyrochosma limitanea ssp. mexicana | Pteridaceae
|
| NOLI2 | Notholaena limitanea Maxon | Argyrochosma limitanea ssp. limitanea | Pteridaceae
|
| NONE4 | Notholaena nealleyi Seaton ex Coult. | Nealley's cloak fern | Pteridaceae
|
| NONE | Notholaena neglecta Maxon | Maxon's cloak fern | Pteridaceae
|
| NONE2 | Notholaena newberryi D.C. Eat. | Cheilanthes newberryi | Pteridaceae
|
| NOPA2 | Notholaena parryi D.C. Eat. | Cheilanthes parryi | Pteridaceae
|
| NOPA3 | Notholaena parvifolia R. Tryon | Argyrochosma microphylla | Pteridaceae
|
| NOSCN | Notholaena schaffneri (Fourn.) Underwood ex Davenport var. nealleyi (Seaton ex Coult.) Weatherby | Notholaena nealleyi | Pteridaceae
|
| NOSIC2 | Notholaena sinuata (Lag. ex Sw.) Kaulfuss var. cochisensis (Goodding) Weatherby | Astrolepis cochisensis ssp. cochisensis | Pteridaceae
|
| NOSII2 | Notholaena sinuata (Lag. ex Sw.) Kaulfuss var. integerrima Hook. | Astrolepis integerrima | Pteridaceae
|
| NOSI | Notholaena sinuata (Lag. ex Sw.) Kaulfuss | Astrolepis sinuata ssp. sinuata | Pteridaceae
|
| NOST | Notholaena standleyi Maxon | star cloak fern | Pteridaceae
|
| NOTR | Notholaena trichomanoides (L.) Desv. | rockslope cloak fern | Pteridaceae
|
| NOTHO | Notholaena R. Br. | cloak fern | Pteridaceae
|
| NOFR2 | Nothopanax fruticosus (L.) Miq. | Polyscias fruticosa | Araliaceae
|
| NOPI | Nothopanax pinnatus (Lam.) Miq. | Polyscias cumingiana | Araliaceae
|
| NORU | Nothoperanema rubiginosum (Brack.) A.R. Sm. & D. Palmer | island lacefern | Dryopteridaceae
|
| NOTHO6 | Nothoperanema (Tagawa) Ching | island lacefern | Dryopteridaceae
|
| NOBI2 | Nothoscordum bivalve (L.) Britt. | crowpoison | Liliaceae
|
| NOBO | Nothoscordum borbonicum Kunth | fragrant false garlic | Liliaceae
|
| NOFR | Nothoscordum fragrans (Vent.) Kunth | Nothoscordum gracile | Liliaceae
|
| NOFR3 | Nothoscordum fragrans auct. non (Vent.) Kunth | Nothoscordum borbonicum | Liliaceae
|
| NOGR3 | Nothoscordum gracile (Ait.) Stearn | slender false garlic | Liliaceae
|
| NOGR4 | Nothoscordum gracile Stearn, non (Ait.) Stearn | Nothoscordum borbonicum | Liliaceae
|
| NOIN3 | Nothoscordum inodorum (Ait.) Nichols. | Allium neapolitanum | Liliaceae
|
| NOIN6 | Nothoscordum inodorum auct. non (Ait.) Nichols. | Nothoscordum borbonicum | Liliaceae
|
| NOTE2 | Nothoscordum texanum M.E. Jones | Texas false garlic | Liliaceae
|
| NOTHO2 | Nothoscordum Kunth | false garlic | Liliaceae
|
| NOTA | Notocactus tabularis (Monv.) N.P. Taylor | Parodia concinna | Cactaceae
|
| NOTOC | Notocactus (K.M. Schumann) Backeb. & F.M. Knuth | notocactus | Cactaceae
|
| NOAM | Notothylas amazonica Spruce | Notothylas breutelii | Notothyladaceae
|
| NOAN | Notothylas angolensis Steph. | Notothylas orbicularis var. orbicularis | Notothyladaceae
|
| NOBR3 | Notothylas breutelii (Gottsche) Gottsche | Breutel's notothylas | Notothyladaceae
|
| NOCU2 | Notothylas cubana Steph. | Notothylas breutelii | Notothyladaceae
|
| NODE2 | Notothylas decurva (Mitt.) Steph. | Notothylas orbicularis var. orbicularis | Notothyladaceae
|
| NOFE2 | Notothylas fertilis (Milde) Milde | Notothylas orbicularis var. orbicularis | Notothyladaceae
|
| NOJA | Notothylas japonica Horik. | Notothylas orbicularis var. orbicularis | Notothyladaceae
|
| NOME | Notothylas melanospora Sull. | Notothylas orbicularis var. orbicularis | Notothyladaceae
|
| NOORO | Notothylas orbicularis (Schwein.) Sull. var. orbicularis | | Notothyladaceae
|
| NOORP | Notothylas orbicularis (Schwein.) Sull. var. pseudotemperata R. M. Schust. | | Notothyladaceae
|
| NOOR | Notothylas orbicularis (Schwein.) Sull. | round notothylas | Notothyladaceae
|
| NOVA | Notothylas valvata Sull. | Notothylas orbicularis var. orbicularis | Notothyladaceae
|
| NOTOT2 | Notothylas Sull. | notothylas | Notothyladaceae
|
| NODI | Nototrichium divaricatum D.H. Lorence | Na Pali rockwort | Amaranthaceae
|
| NOHUP | Nototrichium humile Hbd. var. parvifolium O. Deg. & Sherff | Nototrichium humile | Amaranthaceae
|
| NOHUS | Nototrichium humile Hbd. var. subrhomboideum Sherff | Nototrichium humile | Amaranthaceae
|
| NOHU | Nototrichium humile Hbd. | kaala rockwort | Amaranthaceae
|
| NOSAD | Nototrichium sandwicense (Gray) Hbd. var. decipiens Sherff | Nototrichium sandwicense | Amaranthaceae
|
| NOSAD2 | Nototrichium sandwicense (Gray) Hbd. var. dubium Sherff | Nototrichium sandwicense | Amaranthaceae
|
| NOSAF | Nototrichium sandwicense (Gray) Hbd. var. forbesii Sherff | Nototrichium sandwicense | Amaranthaceae
|
| NOSAH | Nototrichium sandwicense (Gray) Hbd. var. helleri Sherff | Nototrichium sandwicense | Amaranthaceae
|
| NOSAK2 | Nototrichium sandwicense (Gray) Hbd. var. kauaiense (Gray) Hbd. | Nototrichium sandwicense | Amaranthaceae
|
| NOSAK | Nototrichium sandwicense (Gray) Hbd. var. kolekolense Sherff | Nototrichium sandwicense | Amaranthaceae
|