| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| ANCUG | Antitrichia curtipendula (Hedw.) Brid. var. gigantea Sull. & Lesq. | giant antitrichia moss | Leucodontaceae
|
| ANCU3 | Antitrichia curtipendula (Hedw.) Brid. | antitrichia moss | Leucodontaceae
|
| ANTIT2 | Antitrichia Brid. | antitrichia moss | Leucodontaceae
|
| ANCA28 | Antrophyum cajenense (Desv.) Spreng. | forked lineleaf fern | Vittariaceae
|
| ANIN9 | Antrophyum intramarginale (Baker ex Jenman) Kartesz & Gandhi | tufted lineleaf fern | Vittariaceae
|
| ANLA8 | Antrophyum lanceolatum (L.) Kaulfuss | straight lineleaf fern | Vittariaceae
|
| ANLI8 | Antrophyum lineatum (Sw.) Kaulfuss | narrow lineleaf fern | Vittariaceae
|
| ANUR | Antrophyum urbanii Brause | Urban's lineleaf fern | Vittariaceae
|
| ANTRO | Antrophyum Kaulfuss | lineleaf fern | Vittariaceae
|
| ANAN4 | Anulocaulis annulatus (Coville) Standl. | valley ringstem | Nyctaginaceae
|
| ANER | Anulocaulis eriosolenus (Gray) Standl. | Big Bend ringstem | Nyctaginaceae
|
| ANGY | Anulocaulis gypsogenus Waterfall | gypsum ringstem | Nyctaginaceae
|
| ANLEL | Anulocaulis leiosolenus (Torr.) Standl. var. lasianthus I.M. Johnston | southwestern ringstem | Nyctaginaceae
|
| ANLEL2 | Anulocaulis leiosolenus (Torr.) Standl. var. leiosolenus | southwestern ringstem | Nyctaginaceae
|
| ANLE5 | Anulocaulis leiosolenus (Torr.) Standl. | southwestern ringstem | Nyctaginaceae
|
| ANRE3 | Anulocaulis reflexus I.M. Johnston | Texas ringstem | Nyctaginaceae
|
| ANULO | Anulocaulis Standl. | ringstem | Nyctaginaceae
|
| ANCA16 | Anychia canadensis (L.) B.S.P. | Paronychia canadensis | Caryophyllaceae
|
| ANDI7 | Anychia dichotoma Michx. | Paronychia canadensis | Caryophyllaceae
|
| ANPO4 | Anychia polygonoides Raf. | Paronychia fastigiata var. fastigiata | Caryophyllaceae
|
| ANBA5 | Anychiastrum baldwinii (Torr. & Gray) Small | Paronychia baldwinii ssp. baldwinii | Caryophyllaceae
|
| ANMO6 | Anychiastrum montanum Small | Paronychia montana | Caryophyllaceae
|
| ANRI3 | Anychiastrum riparium (Chapman) Small | Paronychia baldwinii ssp. riparia | Caryophyllaceae
|
| ANAM6 | Anzia americana Yoshim. & Sharp | | Parmeliaceae
|
| ANCO25 | Anzia colpodes (Ach.) Stizenb. | anzia lichen | Parmeliaceae
|
| ANOR3 | Anzia ornata (Zahlbr.) Asah. | | Parmeliaceae
|
| ANZIA | Anzia Stizenb. | anzia | Parmeliaceae
|
| ANCA42 | Anzina carneonivea (Anzi) Scheid. | | Trapeliaceae
|
| ANZIN | Anzina Scheid. | anzina | Trapeliaceae
|
| AOLO | Aongstroemia longipes (Somm.) Bruch & Schimp. in B.S.G. | aongstroemia moss | Dicranaceae
|
| AONGS | Aongstroemia Bruch & Schimp. in B.S.G. | aongstroemia moss | Dicranaceae
|
| APCH | Apacheria chiricahuensis C.T. Mason | apachebush | Crossosomataceae
|
| APACH | Apacheria C.T. Mason | apacheria | Crossosomataceae
|
| APSC2 | Apalanthe schweinitzii Planch. | Elodea schweinitzii | Hydrocharitaceae
|
| APAU2 | Apargia autumnalis (L.) Hoffmann | Leontodon autumnalis ssp. autumnalis | Asteraceae
|
| APHI | Apargia hispida (L.) Willd. | Leontodon hispidus ssp. hispidus | Asteraceae
|
| APNU | Apargia nudicaulis (L.) Britt. | Leontodon hirtus | Asteraceae
|
| APBO | Apargidium boreale (Bong.) Torr. & Gray | Microseris borealis | Asteraceae
|
| APHU | Apassalus humistratus (Michx.) Kobuski | Dyschoriste humistrata | Acanthaceae
|
| APOB | Apatoplaca oblongula (H. Magn.) Poelt & Hafellner | Caloplaca oblongula | Teloschistaceae
|
| APIN | Apera interrupta (L.) Beauv. | dense silkybent | Poaceae
|
| APSP | Apera spica-venti (L.) Beauv. | loose silkybent | Poaceae
|
| APERA | Apera Adans. | silkybent | Poaceae
|
| APAR2 | Aphanes arvensis L. | field parsley piert | Rosaceae
|
| APAU | Aphanes australis Rydb. | Aphanes microcarpa | Rosaceae
|
| APMI | Aphanes microcarpa (Boiss. & Reut.) Rothm. | slender parsley piert | Rosaceae
|
| APOC | Aphanes occidentalis (Nutt.) Rydb. | Aphanes arvensis | Rosaceae
|
| APHAN4 | Aphanes L. | parsley piert | Rosaceae
|
| APBL | Aphanisma blitoides Nutt. ex Moq. | San Diego coastalcreeper | Chenopodiaceae
|
| APHAN2 | Aphanisma Nutt. ex Moq. | coastalcreeper | Chenopodiaceae
|
| APCO3 | Aphanolejeunea cornutissima R. M. Schust. | | Lejeuneaceae
|
| APDIC | Aphanolejeunea diaphana (A. Evans) R. M. Schust. var. cristulata (R. M. Schust.) R. M. Schust. | | Lejeuneaceae
|
| APDID | Aphanolejeunea diaphana (A. Evans) R. M. Schust. var. diaphana | | Lejeuneaceae
|
| APDI2 | Aphanolejeunea diaphana (A. Evans) R. M. Schust. | | Lejeuneaceae
|
| APEP | Aphanolejeunea ephemeroides R. M. Schust. | | Lejeuneaceae
|
| APMI3 | Aphanolejeunea minuta R. M. Schust. | | Lejeuneaceae
|
| APTU2 | Aphanolejeunea tuberculata (A. Evans) R. M. Schust. | | Lejeuneaceae
|
| APHAN6 | Aphanolejeunea A. Evans | | Lejeuneaceae
|
| APPA | Aphanorrhegma patens (Hedw.) Lindb. | Physcomitrella patens | Funariaceae
|
| APSE | Aphanorrhegma serratum (Hook. f. & Wils. in Drumm.) Sull. in Gray | serrate aphanorrhegma moss | Funariaceae
|
| APHAN5 | Aphanorrhegma Sull. in Gray | aphanorrhegma moss | Funariaceae
|
| APAR | Aphanostephus arizonicus Gray | Aphanostephus ramosissimus var. humilis | Asteraceae
|
| APHU2 | Aphanostephus humilis (Benth.) Gray | Aphanostephus ramosissimus var. humilis | Asteraceae
|
| APKI | Aphanostephus kidderi Blake | Aphanostephus skirrhobasis var. kidderi | Asteraceae
|
| APPI | Aphanostephus pilosus Buckl. | hairy dozedaisy | Asteraceae
|
| APPO | Aphanostephus potosinus Shinners | Aphanostephus ramosissimus var. humilis | Asteraceae
|
| APRAH | Aphanostephus ramosissimus DC. var. humilis (Benth.) B.L. Turner & Birdsong | plains dozedaisy | Asteraceae
|
| APRAR | Aphanostephus ramosissimus DC. var. ramosissimus | plains dozedaisy | Asteraceae
|
| APRA | Aphanostephus ramosissimus DC. | plains dozedaisy | Asteraceae
|
| APRI | Aphanostephus riddellii Torr. & Gray | Riddell's dozedaisy | Asteraceae
|
| APSKK | Aphanostephus skirrhobasis (DC.) Trel. var. kidderi (Blake) B.L. Turner | Arkansas dozedaisy | Asteraceae
|
| APSKS | Aphanostephus skirrhobasis (DC.) Trel. var. skirrhobasis | Arkansas dozedaisy | Asteraceae
|
| APSKT | Aphanostephus skirrhobasis (DC.) Trel. var. thalassius Shinners | Arkansas dozedaisy | Asteraceae
|
| APSK | Aphanostephus skirrhobasis (DC.) Trel. | Arkansas dozedaisy | Asteraceae
|
| APHAN3 | Aphanostephus DC. | dozedaisy | Asteraceae
|
| APEX | Aphantochaeta exilis Gray | Pentachaeta exilis ssp. exilis | Asteraceae
|
| APES | Aphragmus eschscholtzianus Andrz. ex DC. | Aleutian cress | Brassicaceae
|
| APHRA | Aphragmus Andrz. ex DC. | aphragmus | Brassicaceae
|
| APAR3 | Aphyllon arenosum Suksdorf | Orobanche ludoviciana ssp. ludoviciana | Orobanchaceae
|
| APCO2 | Aphyllon cooperi Gray | Orobanche cooperi ssp. cooperi | Orobanchaceae
|
| APFA | Aphyllon fasciculatum (Nutt.) Torr. & Gray | Orobanche fasciculata | Orobanchaceae
|
| APPI2 | Aphyllon pinorum (Geyer ex Hook.) Gray | Orobanche pinorum | Orobanchaceae
|
| APTU | Aphyllon tuberosum (Gray) Gray | Orobanche bulbosa | Orobanchaceae
|
| APUN2 | Aphyllon uniflorum (L.) Torr. & Gray | Orobanche uniflora | Orobanchaceae
|
| APAN | Apiastrum angustifolium Nutt. | mock parsley | Apiaceae
|
| APIAS | Apiastrum Nutt. ex Torr. & Gray | apiastrum | Apiaceae
|
| APAMT | Apios americana Medik. var. turrigera Fern. | Apios americana | Fabaceae
|
| APAM | Apios americana Medik. | groundnut | Fabaceae
|
| APPR | Apios priceana B.L. Robins. | traveler's delight | Fabaceae
|
| APIOS | Apios Fabr. | groundnut | Fabaceae
|
| APDU2 | Apium dulce Miller | Apium graveolens var. dulce | Apiaceae
|
| APEC | Apium echinatum (Nutt. ex DC.) Benth. & Hook. f. ex S. Wats. | Spermolepis echinata | Apiaceae
|
| APGRD | Apium graveolens L. var. dulce (P. Mill.) DC. | wild celery | Apiaceae
|
| APGRR | Apium graveolens L. var. rapaceum (Miller) Gaudin | celeriac | Apiaceae
|
| APGR2 | Apium graveolens L. | wild celery | Apiaceae
|
| APLE2 | Apium leptophyllum (Pers.) F. Muell. ex Benth. | Cyclospermum leptophyllum | Apiaceae
|
| APNO | Apium nodiflorum (L.) Lag. | European marshwort | Apiaceae
|
| APPE | Apium petroselinum L. | Petroselinum crispum | Apiaceae
|
| APPR2 | Apium prostratum Labill. | prostrate marshwort | Apiaceae
|
| APRA2 | Apium rapaceum Miller | Apium graveolens var. rapaceum | Apiaceae
|
| APRE | Apium repens (Jacq.) Lag. | creeping marshwort | Apiaceae
|