|
|
|
|
Plant List
Indexed Alphabetically by Common Name
N-O
For a list of plants indexed by Scientific Name, click here
--Please wait while data loads--
| National Common Name | Scientific Name with Author | Symbol | Family | |
| Na Pali sandmat | Chamaesyce eleanoriae D.H. Lorence & W.L. Wagner | CHEL7 | Euphorbiaceae | |
| Nadvornik's horsehair lichen | Bryoria nadvornikiana (Gyelnik) Brodo & D. Hawksw. | BRNA60 | Parmeliaceae | |
| naked albizia | Albizia carbonaria Britt. | ALCA8 | Fabaceae | |
| naked mariposa lily | Calochortus nudus S. Wats. | CANU2 | Liliaceae | |
| naked milkvetch | Astragalus serenoi (Kuntze) Sheldon | ASSE4 | Fabaceae | |
| naked milkvetch | Astragalus serenoi (Kuntze) Sheldon var. serenoi | ASSES3 | Fabaceae | |
| naked milkvetch | Astragalus serenoi (Kuntze) Sheldon var. sordescens Barneby | ASSES | Fabaceae | |
| naked oat | Avena nuda L. [excluded] | AVNU2 | Poaceae | |
| naked sedge | Carex nudata W. Boott | CANU5 | Cyperaceae | |
| nakedstem alkaliweed | Cressa nudicaulis Griseb. | CRNU | Convolvulaceae | |
| nakedstem hawksbeard | Crepis pleurocarpa Gray | CRPL | Asteraceae | |
| nakedstem livingvase | Aechmea nudicaulis (L.) Griseb. | AENU | Bromeliaceae | |
| nakedwood | Colubrina L.C. Rich. ex Brongn. | COLUB | Rhamnaceae | |
| nalta jute | Corchorus olitorius L. | COOL | Tiliaceae | |
| Nantucket serviceberry | Amelanchier nantucketensis Bickn. | AMNA2 | Rosaceae | |
| Napa cryptantha | Cryptantha hispidula Greene ex Brand | CRHI | Boraginaceae | |
| Napa false indigo | Amorpha californica Nutt. var. napensis Jepson | AMCAN | Fabaceae | |
| Napa milkvetch | Astragalus clarianus Jepson | ASCL6 | Fabaceae | |
| Napali coast papala | Charpentiera densiflora Sohmer | CHDE3 | Amaranthaceae | |
| Napoleon's plume | Bauhinia monandra Kurz | BAMO2 | Fabaceae | |
| narcissus anemone | Anemone narcissiflora L. | ANNA | Ranunculaceae | |
| narcissus anemone | Anemone narcissiflora L. var. monantha DC. | ANNAM2 | Ranunculaceae | |
| narcissus anemone | Anemone narcissiflora L. var. villosissima DC. | ANNAV3 | Ranunculaceae | |
| narcissus anemone | Anemone narcissiflora L. var. zephyra (A. Nels.) Dutton & Keener | ANNAZ2 | Ranunculaceae | |
| narrow corncockle | Agrostemma brachyloba (Fenzl) Hammer | AGBR4 | Caryophyllaceae | |
| narrow helmet orchid | Cranichis tenuis Reichenb. f. [excluded] | CRTE6 | Orchidaceae | |
| narrow lineleaf fern | Antrophyum lineatum (Sw.) Kaulfuss | ANLI8 | Vittariaceae | |
| narrow strapfern | Campyloneurum angustifolium (Sw.) Fée | CAAN9 | Polypodiaceae | |
| narrowfruit sedge | Carex specifica Bailey | CASP4 | Cyperaceae | |
| narrowleaf angelon | Angelonia angustifolia Benth. | ANAN5 | Scrophulariaceae | |
| narrowleaf arnica | Arnica angustifolia Vahl | ARAN5 | Asteraceae | |
| narrowleaf arnica | Arnica angustifolia Vahl ssp. angustifolia | ARANA | Asteraceae | |
| narrowleaf arnica | Arnica angustifolia Vahl ssp. tomentosa (Macoun) G.W. Douglas & G. Ruyle-Douglas | ARANT | Asteraceae | |
| narrowleaf bittercress | Cardamine impatiens L. | CAIM | Brassicaceae | |
| narrowleaf blue eyed Mary | Collinsia linearis Gray | COLI | Scrophulariaceae | |
| narrow-leaf bottlebrush | Callistemon linearis (Schrad. & J. C. Wendl.) Sweet | CALI24 | Myrtaceae | |
| narrowleaf brickellbush | Brickellia oblongifolia Nutt. var. linifolia (D.C. Eat.) B.L. Robins. | BROBL | Asteraceae | |
| narrowleaf crucianella | Crucianella angustifolia L. | CRAN11 | Rubiaceae | |
| narrowleaf desert honeysuckle | Anisacanthus linearis (Hagen) Henrickson & Lott | ANLI3 | Acanthaceae | |
| narrowleaf goldenaster | Chrysopsis linearifolia Semple | CHLI4 | Asteraceae | |
| narrowleaf goldenaster | Chrysopsis linearifolia Semple ssp. linearifolia | CHLIL | Asteraceae | |
| narrowleaf goosefoot | Chenopodium leptophyllum (Moq.) Nutt. ex S. Wats. | CHLE4 | Chenopodiaceae | |
| narrowleaf grapefern | Botrychium lineare W.H. Wagner | BOLI7 | Ophioglossaceae | |
| narrowleaf hawksbeard | Crepis tectorum L. | CRTE3 | Asteraceae | |
| narrowleaf midsorus fern | Blechnum polypodioides Raddi | BLPO | Blechnaceae | |
| narrowleaf milkvetch | Astragalus pectinatus (Dougl. ex Hook.) Dougl. ex G. Don | ASPE5 | Fabaceae | |
| narrowleaf onion | Allium amplectens Hook. | ALAM2 | Liliaceae | |
| narrowleaf pussytoes | Antennaria stenophylla (Gray) Gray | ANST2 | Asteraceae | |
| narrowleaf rhombopod | Cleomella angustifolia Torr. | CLAN | Capparaceae | |
| narrowleaf silverbush | Argythamnia lanceolata (Benth.) Muell.-Arg. | ARLA12 | Euphorbiaceae | |
| narrowleaf soap plant | Chlorogalum angustifolium Kellogg | CHAN2 | Liliaceae | |
| narrowleaf spiderling | Boerhavia linearifolia Gray | BOLI2 | Nyctaginaceae | |
| narrowleaf spineflower | Chorizanthe angustifolia Nutt. | CHAN3 | Polygonaceae | |
| narrowleaf suncup | Camissonia refracta (S. Wats.) Raven | CARE2 | Onagraceae | |
| narrowleaf terciopelo | Clidemia angustilamina Judd & Skean | CLAN8 | Melastomataceae | |
| narrowleaf thorow wax | Bupleurum odontites L. | BUOD2 | Apiaceae | |
| narrowleaf water plantain | Alisma gramineum Lej. | ALGR | Alismataceae | |
| narrow-leaf wattle | Acacia mucronata Willd. ex H. L. Wendl. | ACMU6 | Fabaceae | |
| narrowleaf wild leek | Allium burdickii (Hanes) A.G. Jones | ALBU2 | Liliaceae | |
| narrow-leaved iceplant | Conicosia N.R. Br. | CONIC | Aizoaceae | |
| narrow-leaved iceplant | Conicosia pugioniformis (L.) N.E. Br. | COPU18 | Aizoaceae | |
| narrowpod sensitive pea | Chamaecrista lineata (Sw.) Greene | CHLI5 | Fabaceae | |
| narrowpod sensitive pea | Chamaecrista lineata (Sw.) Greene var. brachyloba (Griseb.) Irwin & Barneby | CHLIB | Fabaceae | |
| narrowpod sensitive pea | Chamaecrista lineata (Sw.) Greene var. keyensis (Pennell) Irwin & Barneby | CHLIK | Fabaceae | |
| narrowstem cryptantha | Cryptantha gracilis Osterhout | CRGR3 | Boraginaceae | |
| Nashville hawthorn | Crataegus ater Ashe | CRAT3 | Rosaceae | |
| Natal glorybower | Clerodendrum glabrum E. Mey. | CLGL2 | Verbenaceae | |
| Natal plum | Anechites nerium (Aubl.) Urban | ANNE2 | Apocynaceae | |
| Nathorist's aspicilia | Aspicilia nathoristii (Lynge) J. W. Thomson | ASNA7 | Hymeneliaceae | |
| native begonia | Begonia decandra Pavón ex A. DC. | BEDE2 | Begoniaceae | |
| native caper | Capparis sandwichiana DC. | CASA4 | Capparaceae | |
| native sedge | Carex vernacula Bailey | CAVE5 | Cyperaceae | |
| Naturita milkvetch | Astragalus naturitensis Payson | ASNA | Fabaceae | |
| Navajo saltbush | Atriplex navajoensis C.A. Hanson | ATNA | Chenopodiaceae | |
| Navajo sedge | Carex specuicola J.T. Howell | CASP9 | Cyperaceae | |
| Navajo thistle | Cirsium navajoense Moore & Frankton | CINA | Asteraceae | |
| Navasota false foxglove | Agalinis navasotensis M. Dubrule & J. Canne-Hilliker | AGNA | Scrophulariaceae | |
| nealie | Acacia rigens A. Cunn. ex G. Don | ACRI6 | Fabaceae | |
| Neal's manfern | Cibotium nealiae O. Deg. | CINE2 | Dicksoniaceae | |
| nearlyblack sedge | Carex subnigricans Stacey | CASU7 | Cyperaceae | |
| Nebraska sedge | Carex nebrascensis Dewey | CANE2 | Cyperaceae | |
| necklace sedge | Carex projecta Mackenzie | CAPR9 | Cyperaceae | |
| necklace spike sedge | Carex ormostachya Wieg. | CAOR5 | Cyperaceae | |
| needle grama | Bouteloua aristidoides (Kunth) Griseb. | BOAR | Poaceae | |
| needle grama | Bouteloua aristidoides (Kunth) Griseb. var. aristidoides | BOARA | Poaceae | |
| needle lichen | Chaenotheca brachypoda (Ach.) Tibell | CHBR9 | Coniocybaceae | |
| needle lichen | Chaenotheca brunneola (Ach.) Mull Arg. | CHBR10 | Coniocybaceae | |
| needle lichen | Chaenotheca chlorella (Ach.) Mull. Arg. | CHCH13 | Coniocybaceae | |
| needle lichen | Chaenotheca chrysocephala (Turner ex Ach.) Th. Fr. | CHCH14 | Coniocybaceae | |
| needle lichen | Chaenotheca cinerea (Pers.) Tibell | CHCI4 | Coniocybaceae | |
| needle lichen | Chaenotheca ferruginea (Turner & Borrer) Mig. | CHFE7 | Coniocybaceae | |
| needle lichen | Chaenotheca furfuracea (L.) Tibell | CHFU3 | Coniocybaceae | |
| needle lichen | Chaenotheca gracillima (Vainio) Tibell | CHGR20 | Coniocybaceae | |
| needle lichen | Chaenotheca laevigata Nadv. | CHLA22 | Coniocybaceae | |
| needle lichen | Chaenotheca phaeocephala (Turner) Th. Fr. | CHPH | Coniocybaceae | |
| needle lichen | Chaenotheca stemonea (Ach.) Mull. Arg. | CHST9 | Coniocybaceae | |
| needle lichen | Chaenotheca subroscida (Eitner) Zahlbr. | CHSU14 | Coniocybaceae | |
| needle lichen | Chaenotheca Th. Fr. | CHAEN4 | Coniocybaceae | |
| needle lichen | Chaenotheca trichialis (Ach.) Th. Fr. | CHTR12 | Coniocybaceae | |
| needle lichen | Chaenotheca xyloxena Nadv. | CHXY | Coniocybaceae | |
| Needle Mountain milkvetch | Astragalus eurylobus (Barneby) Barneby | ASEU3 | Fabaceae | |
| needlegrass | Achnatherum Beauv. | ACHNA | Poaceae | |
| needleleaf sedge | Carex duriuscula C.A. Mey. | CADU6 | Cyperaceae | |
| needleroot bentspur orchid | Campylocentrum filiforme (Sw.) Cogn. ex Kuntze | CAFI10 | Orchidaceae | |
| needletip trumpets | Acleisanthes acutifolia Standl. | ACAC | Nyctaginaceae | |
| neem | Azadirachta indica A. Juss. | AZIN2 | Meliaceae | |
| neglected balsamroot | Balsamorhiza hookeri (Hook.) Nutt. var. neglecta (Sharp) Cronq. | BAHON | Asteraceae | |
| Nelson's brachythecium moss | Brachythecium nelsonii Grout | BRNE4 | Brachytheciaceae | |
| Nelson's brickellbush | Brickellia nelsonii B.L. Robins. [excluded] | BRNE | Asteraceae | |
| Nelson's milkvetch | Astragalus nelsonianus Barneby | ASNE3 | Fabaceae | |
| Nelson's sedge | Carex nelsonii Mackenzie | CANE3 | Cyperaceae | |
| Neobrackenridge's spleenwort | Asplenium neobrackenridgei W.H. Wagner | ASNE10 | Aspleniaceae | |
| neon dot lichen | Arthonia neoni de Lesd. | ARNE10 | Arthoniaceae | |
| Neon's orange lichen | Caloplaca neonii de Lesd. | CANE16 | Teloschistaceae | |
| Nepal alder | Alnus nepalensis D. Don | ALNE2 | Betulaceae | |
| nerveless woodland sedge | Carex leptonervia (Fern.) Fern. | CALE11 | Cyperaceae | |
| neststraw | Ancistrocarphus Gray | ANCIS2 | Asteraceae | |
| netbush | Calothamnus Labill. | CALOT3 | Myrtaceae | |
| netleaf hackberry | Celtis laevigata Willd. var. reticulata (Torr.) L. Benson | CELAR | Ulmaceae | |
| netleaf leather flower | Clematis reticulata Walt. | CLRE | Ranunculaceae | |
| netted anoda | Anoda reticulata S. Wats. | ANRE2 | Malvaceae | |
| netted pawpaw | Asimina reticulata Shuttlw. ex Chapman | ASRE7 | Annonaceae | |
| nettleleaf giant hyssop | Agastache urticifolia (Benth.) Kuntze | AGUR | Lamiaceae | |
| nettleleaf giant hyssop | Agastache urticifolia (Benth.) Kuntze var. glaucifolia (Heller) Cronq. | AGURG | Lamiaceae | |
| nettleleaf giant hyssop | Agastache urticifolia (Benth.) Kuntze var. urticifolia | AGURU | Lamiaceae | |
| nettleleaf goosefoot | Chenopodium murale L. | CHMU2 | Chenopodiaceae | |
| Nevada agave | Agave utahensis Engelm. var. nevadensis Engelm. ex Greenm. & Roush | AGUTN | Agavaceae | |
| Nevada arnica | Arnica nevadensis Gray | ARNE3 | Asteraceae | |
| Nevada cracked lichen | Acarospora nevadensis H. Magn. | ACNE7 | Acarosporaceae | |
| Nevada cryptantha | Cryptantha nevadensis A. Nels. & Kennedy | CRNE2 | Boraginaceae | |
| Nevada cryptantha | Cryptantha nevadensis A. Nels. & Kennedy var. nevadensis | CRNEN | Boraginaceae | |
| Nevada cryptantha | Cryptantha nevadensis A. Nels. & Kennedy var. rigida I.M. Johnston | CRNER | Boraginaceae | |
| Nevada dustymaiden | Chaenactis nevadensis (Kellogg) Gray | CHNE | Asteraceae | |
| Nevada goosefoot | Chenopodium nevadense Standl. | CHNE4 | Chenopodiaceae | |
| Nevada milkvetch | Astragalus bisulcatus (Hook.) Gray var. nevadensis (M.E. Jones) Barneby | ASBIN | Fabaceae | |
| Nevada needlegrass | Achnatherum nevadense (B.L. Johnston) Barkworth | ACNE10 | Poaceae | |
| Nevada onion | Allium nevadense S. Wats. | ALNE | Liliaceae | |
| Nevada pussypaws | Cistanthe parryi (Gray) Hershkovitz var. nevadensis (J.T. Howell) Kartesz & Gandhi | CIPAN | Portulacaceae | |
| Nevada rockcress | Arabis perstellata E.L. Braun | ARPE3 | Brassicaceae | |
| Nevada sumpweed | Chorisiva nevadensis (M.E. Jones) Rydb. | CHNE12 | Asteraceae | |
| Nevada suncup | Camissonia nevadensis (Kellogg) Raven | CANE11 | Onagraceae | |
| Nevin's bird's-beak | Cordylanthus nevinii Gray | CONE | Scrophulariaceae | |
| Nevin's brickellbush | Brickellia nevinii Gray | BRNE2 | Asteraceae | |
| Nevin's woolly sunflower | Constancea nevinii (Gray) B.G. Baldwin | CONE9 | Asteraceae | |
| Nevius' garlic | Allium nevii S. Wats. | ALNE4 | Liliaceae | |
| New Caledonia pine | Araucaria columnaris (Forster) Hook. | ARCO32 | Araucariaceae | |
| New England bryhnia moss | Bryhnia novae-angliae (Sull. & Lesq. in Sull.) Grout | BRNO4 | Brachytheciaceae | |
| New England sedge | Carex novae-angliae Schwein. | CANO4 | Cyperaceae | |
| New Holland rattlepod | Crotalaria novae-hollandiae DC. | CRNO4 | Fabaceae | |
| New Jersey tea | Ceanothus americanus L. | CEAM | Rhamnaceae | |
| New London hawthorn | Crataegus spatiosa Sarg. | CRSP5 | Rosaceae | |
| New Mexican disc lichen | Buellia novomexicana de Lesd. | BUNO2 | Physciaceae | |
| New Mexican nodding onion | Allium cernuum Roth var. neomexicanum (Rydb.) J.F. Macbr. | ALCEN | Liliaceae | |
| New Mexico copperleaf | Acalypha neomexicana Muell.-Arg. | ACNE | Euphorbiaceae | |
| New Mexico cryptantha | Cryptantha albida (Kunth) I.M. Johnston | CRAL | Boraginaceae | |
| New Mexico goosefoot | Chenopodium neomexicanum Standl. | CHNE3 | Chenopodiaceae | |
| New Mexico goosefoot | Chenopodium neomexicanum Standl. var. neomexicanum | CHNEN | Chenopodiaceae | |
| New Mexico maple | Acer glabrum Torr. var. neomexicanum (Greene) Kearney & Peebles | ACGLN2 | Aceraceae | |
| New Mexico milkvetch | Astragalus neomexicanus Woot. & Standl. | ASNE4 | Fabaceae | |
| New Mexico needlegrass | Achnatherum perplexum Hoge & Barkworth | ACPE13 | Poaceae | |
| New Mexico orange lichen | Caloplaca novomexicana (Fink) | CANO5 | Teloschistaceae | |
| New Mexico silverbush | Argythamnia neomexicana Muell.-Arg. | ARNE2 | Euphorbiaceae | |
| New Mexico spiny milkvetch | Astragalus kentrophyta Gray var. neomexicanus (Barneby) Barneby | ASKEN | Fabaceae | |
| New Mexico thistle | Cirsium neomexicanum Gray | CINE | Asteraceae | |
| New York hawthorn | Crataegus desueta Sarg. | CRDE3 | Rosaceae | |
| New York Mountain cryptantha | Cryptantha tumulosa (Payson) Payson | CRTU | Boraginaceae | |
| Newberry's lipfern | Cheilanthes newberryi (D.C. Eat.) Domin | CHNE2 | Pteridaceae | |
| Newberry's milkvetch | Astragalus newberryi Gray | ASNE6 | Fabaceae | |
| Newberry's milkvetch | Astragalus newberryi Gray var. aquarii Isely | ASNEA | Fabaceae | |
| Newberry's milkvetch | Astragalus newberryi Gray var. blyae (Rose ex Rydb.) Barneby | ASNEB | Fabaceae | |
| Newberry's milkvetch | Astragalus newberryi Gray var. castoreus M.E. Jones | ASNEC | Fabaceae | |
| Newberry's milkvetch | Astragalus newberryi Gray var. newberryi | ASNEN | Fabaceae | |
| Newberry's tickseed | Coreopsis californica (Nutt.) H.K. Sharsmith var. newberryi (Gray) E.B. Sm. | COCAN | Asteraceae | |
| Nez Perce mariposa lily | Calochortus macrocarpus Dougl. var. maculosus (A. Nels. & J.F. Macbr.) A. Nels. & J.F. Macbr. | CAMAM | Liliaceae | |
| ngai camphor | Blumea balsamifera (L.) DC. | BLBA2 | Asteraceae | |
| Nickels' cactus | Coryphantha nickelsiae (K. Brandeg.) Britt. & Rose | CONI16 | Cactaceae | |
| nicker | Caesalpinia L. | CAESA | Fabaceae | |
| night jessamine | Cestrum nocturnum L. | CENO | Solanaceae | |
| nightblooming false bindweed | Calystegia atriplicifolia Hallier f. | CAAT9 | Convolvulaceae | |
| nightblooming false bindweed | Calystegia atriplicifolia Hallier f. ssp. atriplicifolia | CAATA | Convolvulaceae | |
| nightblooming false bindweed | Calystegia atriplicifolia Hallier f. ssp. buttensis Brummitt | CAATB | Convolvulaceae | |
| nightcaps | Anemone quinquefolia L. var. minima (DC.) Frodin | ANQUM2 | Ranunculaceae | |
| nightcaps | Anemone quinquefolia L. var. quinquefolia | ANQUQ | Ranunculaceae | |
| nigua | Cornutia obovata Urban | COOB4 | Verbenaceae | |
| Nikko fir | Abies homolepis Sieb. and Zucc. | ABHO | Pinaceae | |
| Nile grass | Acroceras macrum Stapf | ACMA5 | Poaceae | |
| nipple beehive cactus | Coryphantha macromeris (Engelm.) Lem. | COMA14 | Cactaceae | |
| nipple beehive cactus | Coryphantha macromeris (Engelm.) Lem. var. macromeris | COMAM2 | Cactaceae | |
| Nissenan manzanita | Arctostaphylos nissenana Merriam | ARNI4 | Ericaceae | |
| nitbearing lipfern | Cheilanthes lendigera (Cav.) Sw. | CHLE2 | Pteridaceae | |
| Nixon's hawthorn | Crataegus nananixonii Phipps & R. O'Kennon | CRNA4 | Rosaceae | |
| noble fir | Abies procera Rehd. | ABPR | Pinaceae | |
| noble yarrow | Achillea nobilis L. | ACNO | Asteraceae | |
| nodding arnica | Arnica lessingii Greene | ARLE2 | Asteraceae | |
| nodding beggartick | Bidens cernua L. | BICE | Asteraceae | |
| nodding bird's-beak | Cordylanthus laxiflorus Gray | COLA4 | Scrophulariaceae | |
| nodding brome | Bromus anomalus Rupr. ex Fourn. | BRAN | Poaceae | |
| nodding chickweed | Cerastium nutans Raf. | CENU2 | Caryophyllaceae | |
| nodding chickweed | Cerastium nutans Raf. var. nutans | CENUN | Caryophyllaceae | |
| nodding chickweed | Cerastium nutans Raf. var. obtectum Kearney & Peebles | CENUO | Caryophyllaceae | |
| nodding milkweed | Asclepias glaucescens Kunth | ASGL5 | Asclepiadaceae | |
| nodding nixie | Apteria aphylla (Nutt.) Barnh. ex Small | APAP | Burmanniaceae | |
| nodding onion | Allium cernuum Roth | ALCE2 | Liliaceae | |
| nodding onion | Allium cernuum Roth var. cernuum | ALCEC2 | Liliaceae | |
| nodding onion | Allium cernuum Roth var. obtusum Cockerell ex J.F. Macbr. | ALCEO | Liliaceae | |
| nodding plumeless thistle | Carduus nutans L. | CANU4 | Asteraceae | |
| nodding rockcress | Arabis demissa Greene | ARDE | Brassicaceae | |
| nodding rockcress | Arabis demissa Greene var. demissa | ARDED | Brassicaceae | |
| nodding rockcress | Arabis demissa Greene var. languida Rollins | ARDEL | Brassicaceae | |
| nodding sedge | Carex gynandra Schwein. | CAGY4 | Cyperaceae | |
| nodding strap airplant | Catopsis nutans (Sw.) Griseb. | CANU7 | Bromeliaceae | |
| nodule cracked lichen | Acarospora nodulosa (Dufour) Hue | ACNO6 | Acarosporaceae | |
| nodule cracked lichen | Acarospora nodulosa (Dufour) Hue var. nodulosa | ACNON | Acarosporaceae | |
| Norfolk Island pine | Araucaria heterophylla (Salisb.) Franco | ARHE12 | Araucariaceae | |
| North African knapweed | Centaurea diluta Ait. | CEDI4 | Asteraceae | |
| northeastern sedge | Carex cryptolepis Mackenzie | CACR9 | Cyperaceae | |
| northern beantree | Bauhinia carronii F. Muell. | BACA15 | Fabaceae | |
| northern bentgrass | Agrostis mertensii Trin. | AGME3 | Poaceae | |
| northern birch | Betula borealis Spach | BEBO | Betulaceae | |
| northern blue monkshood | Aconitum noveboracense Gray ex Coville | ACNO2 | Ranunculaceae | |
| northern bluethread | Burmannia biflora L. | BUBI | Burmanniaceae | |
| northern bog sedge | Carex gynocrates Wormsk. ex Drej. | CAGY2 | Cyperaceae | |
| northern catalpa | Catalpa speciosa (Warder) Warder ex Engelm. | CASP8 | Bignoniaceae | |
| northern clarkia | Clarkia borealis E. Small | CLBO4 | Onagraceae | |
| northern clarkia | Clarkia borealis E. Small ssp. borealis | CLBOB | Onagraceae | |
| northern cluster sedge | Carex arcta Boott | CAAR2 | Cyperaceae | |
| northern false coolwort | Bolandra oregana S. Wats. | BOOR | Saxifragaceae | |
| northern freckled milkvetch | Astragalus lentiginosus Dougl. ex Hook. var. albifolius M.E. Jones | ASLEA | Fabaceae | |
| northern golden saxifrage | Chrysosplenium tetrandrum (Lund ex Malmgr.) Th. Fries | CHTE3 | Saxifragaceae | |
| northern groundcone | Boschniakia rossica (Cham. & Schlecht.) Fedtsch. | BORO | Orobanchaceae | |
| northern hawthorn | Crataegus dissona Sarg. | CRDI10 | Rosaceae | |
| northern Indian paintbrush | Castilleja hyperborea Pennell | CAHY6 | Scrophulariaceae | |
| northern long sedge | Carex folliculata L. | CAFO6 | Cyperaceae | |
| northern maidenhair | Adiantum pedatum L. | ADPE | Pteridaceae | |
| northern moonwort | Botrychium pinnatum St. John | BOPI | Ophioglossaceae | |
| northern orange lichen | Caloplaca montana (de Lesd.) | CAMO27 | Teloschistaceae | |
| northern reedgrass | Calamagrostis stricta (Timm) Koel. ssp. inexpansa (Gray) C.W. Greene | CASTI3 | Poaceae | |
| northern rimmed lichen | Aspicilia nordlandica (H. Magn.) Degel. | ASNO6 | Hymeneliaceae | |
| northern sedge | Carex deflexa Hornem. | CADE7 | Cyperaceae | |
| northern shorthusk | Brachyelytrum aristosum (Michx.) Trel. | BRAR9 | Poaceae | |
| northern singlespike sedge | Carex scirpoidea Michx. | CASC10 | Cyperaceae | |
| northern singlespike sedge | Carex scirpoidea Michx. ssp. scirpoidea | CASCS8 | Cyperaceae | |
| northern water plantain | Alisma triviale Pursh | ALTR7 | Alismataceae | |
| northern water-starwort | Callitriche hermaphroditica L. | CAHE2 | Callitrichaceae | |
| northern-rockcress | Braya Sternb. & Hoppe | BRAYA | Brassicaceae | |
| Northwest Territory sedge | Carex utriculata Boott | CAUT | Cyperaceae | |
| northwestern Indian paintbrush | Castilleja angustifolia (Nutt.) G. Don | CAAN7 | Scrophulariaceae | |
| northwestern Indian paintbrush | Castilleja angustifolia (Nutt.) G. Don var. angustifolia | CAANA3 | Scrophulariaceae | |
| northwestern Indian paintbrush | Castilleja angustifolia (Nutt.) G. Don var. flavescens (Pennell ex Edwin) N. Holmgren | CAANF | Scrophulariaceae | |
| northwestern sedge | Carex concinnoides Mackenzie | CACO11 | Cyperaceae | |
| Norway bryoxiphium moss | Bryoxiphium norvegicum (Brid.) Mitt. | BRNO6 | Bryoxiphiaceae | |
| Norway maple | Acer platanoides L. | ACPL | Aceraceae | |
| Norway sedge | Carex norvegica Retz. | CANO2 | Cyperaceae | |
| Norway sedge | Carex norvegica Retz. ssp. norvegica | CANON2 | Cyperaceae | |
| notable wattle | Acacia notabilis F. Muell. | ACNO5 | Fabaceae | |
| Notaris' soot lichen | Cyphelium notarisii (Tul.) Blomb. & Forss. | CYNO3 | Caliciaceae | |
| Nottoway Valley brome | Bromus nottowayanus Fern. | BRNO | Poaceae | |
| nude hawthorn | Crataegus nuda Sarg. | CRNU4 | Rosaceae | |
| nutgrass | Cyperus rotundus L. | CYRO | Cyperaceae | |
| nutmeg hickory | Carya myristiciformis (Michx. f.) Nutt. | CAMY | Juglandaceae | |
| Nuttall's false foxglove | Agalinis nuttallii Shinners | AGNU | Scrophulariaceae | |
| Nuttall's goosefoot | Chenopodium berlandieri Moq. ssp. nuttalliae (Safford) H. D. Wilson & Heiser | CHBEN | Chenopodiaceae | |
| Nuttall's little rose | Chamaerhodos erecta (L.) Bunge ssp. nuttallii (Pickering ex Rydb.) Hultén | CHERN | Rosaceae | |
| Nuttall's milkvetch | Astragalus nuttallii (Torr. & Gray) J.T. Howell | ASNU5 | Fabaceae | |
| Nuttall's milkvetch | Astragalus nuttallii (Torr. & Gray) J.T. Howell var. nuttallii | ASNUN2 | Fabaceae | |
| Nuttall's milkvetch | Astragalus nuttallii (Torr. & Gray) J.T. Howell var. virgatus (Gray ex Brewer & S. Wats.) Barneby | ASNUV | Fabaceae | |
| Nuttall's rayless goldenrod | Bigelowia nuttallii L.C. Anders. | BINU2 | Asteraceae | |
| Nuttall's rockcress | Arabis nuttallii B.L. Robins. | ARNU | Brassicaceae | |
| Nuttall's saltbush | Atriplex nuttallii S. Wats. | ATNU2 | Chenopodiaceae | |
| Nuttall's thistle | Cirsium nuttallii DC. | CINU | Asteraceae | |
| Nuttall's toothwort | Cardamine nuttallii Greene | CANU17 | Brassicaceae | |
| Nuttall's toothwort | Cardamine nuttallii Greene var. covilleana (O.E. Schultz) Rollins | CANUC | Brassicaceae | |
| Nuttall's toothwort | Cardamine nuttallii Greene var. dissecta (O.E. Schultz) Rollins | CANUD | Brassicaceae | |
| Nuttall's toothwort | Cardamine nuttallii Greene var. gemmata (Greene) Rollins | CANUG | Brassicaceae | |
| Nuttall's water-starwort | Callitriche pedunculosa Nutt. | CAPE44 | Callitrichaceae | |
| Nuttall's wild indigo | Baptisia nuttalliana Small | BANU2 | Fabaceae | |
| Nutzotin milkvetch | Astragalus nutzotinensis Rouss. | ASNU6 | Fabaceae | |
| Nye gilia | Aliciella nyensis (Reveal) J.M. Porter | ALNY2 | Polemoniaceae | |
| Nye milkvetch | Astragalus nyensis Barneby | ASNY2 | Fabaceae | |
| Oahu beggarticks | Bidens populifolia Sherff | BIPO2 | Asteraceae | |
| Oahu clermontia | Clermontia oblongifolia Gaud. | CLOB2 | Campanulaceae | |
| Oahu clermontia | Clermontia oblongifolia Gaud. ssp. brevipes (F. Wimmer) Lammers | CLOBB | Campanulaceae | |
| Oahu clermontia | Clermontia oblongifolia Gaud. ssp. mauiensis (Rock) Lammers | CLOBM | Campanulaceae | |
| Oahu clermontia | Clermontia oblongifolia Gaud. ssp. oblongifolia | CLOBO | Campanulaceae | |
| Oahu cyanea | Cyanea hardyi Rock | CYHA7 | Campanulaceae | |
| O'ahu cyanea | Cyanea calycina (Cham.) Lammers | CYCA23 | Campanulaceae | |
| Oahu cyrtandra | Cyrtandra laxiflora Mann | CYLA8 | Gesneriaceae | |
| Oahu flatsedge | Cyperus hypochlorus Hbd. | CYHY2 | Cyperaceae | |
| Oahu flatsedge | Cyperus hypochlorus Hbd. var. ?kauaiensis Kükenth. | CYHYK | Cyperaceae | |
| Oahu flatsedge | Cyperus hypochlorus Hbd. var. brevior Kükenth. | CYHYB | Cyperaceae | |
| Oahu flatsedge | Cyperus hypochlorus Hbd. var. hypochlorus | CYHYH | Cyperaceae | |
| Oahu kihifern | Adenophorus oahuensis (Copeland) Bishop | ADOA | Grammitidaceae | |
| Oahu mirrorplant | Coprosma longifolia Gray | COLO4 | Rubiaceae | |
| Oahu rollandia | Cyanea humboldtiana (Gaud.) Lammers, Givnish & Sytsma | CYHU2 | Campanulaceae | |
| Oahu sandmat | Chamaesyce deppeana (Boiss.) Millsp. | CHDE8 | Euphorbiaceae | |
| Oahu sedge | Carex wahuensis C.A. Mey. | CAWA | Cyperaceae | |
| Oahu sedge | Carex wahuensis C.A. Mey. ssp. rubiginosa (R.W. Krauss) T. Koyama | CAWAR2 | Cyperaceae | |
| Oahu sedge | Carex wahuensis C.A. Mey. ssp. wahuensis | CAWAW | Cyperaceae | |
| Oahu wormwood | Artemisia australis Less. | ARAU3 | Asteraceae | |
| Oakland mariposa lily | Calochortus umbellatus Wood | CAUM | Liliaceae | |
| oakleaf carica | Carica quercifolia (A. St. Hil.) Hieron. | CAQU9 | Caricaceae | |
| oakleaf cyanea | Cyanea quercifolia (Hbd.) F. Wimmer | CYQU | Campanulaceae | |
| oakleaf goosefoot | Chenopodium glaucum L. | CHGL3 | Chenopodiaceae | |
| oat | Avena L. | AVENA | Poaceae | |
| oatgrass | Arrhenatherum Beauv. | ARRHE | Poaceae | |
| Obispo Indian paintbrush | Castilleja densiflora (Benth.) Chuang & Heckard ssp. obispoensis (Keck) Chuang & Heckard | CADEO | Scrophulariaceae | |
| Obispo suncup | Camissonia campestris (Greene) Raven ssp. obispoensis Raven | CACAO | Onagraceae | |
| oblique maidenhair | Adiantum obliquum Willd. | ADOB | Pteridaceae | |
| obliqueleaf trumpets | Acleisanthes anisophylla Gray | ACAN2 | Nyctaginaceae | |
| obliqueseeded jackbean | Canavalia plagiosperma Piper | CAPL16 | Fabaceae | |
| oblong bryum moss | Bryum oblongum Lindb. | BROB3 | Bryaceae | |
| oblongfruit serviceberry | Amelanchier bartramiana (Tausch) M. Roemer | AMBA | Rosaceae | |
| oblongleaf orache | Atriplex oblongifolia Waldst. & Kit. | ATOB2 | Chenopodiaceae | |
| obovate andreaea moss | Andreaea obovata Thed. | ANOB8 | Andreaeaceae | |
| obscure Indian paintbrush | Castilleja cryptantha Pennell & G.N. Jones | CACR14 | Scrophulariaceae | |