| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| ATAL3 | Atelophragma alpiniforme Rydb. | Astragalus robbinsii var. alpiniformis | Fabaceae
|
| ATAL2 | Atelophragma alpinum (L.) Rydb. | Astragalus alpinus var. alpinus | Fabaceae
|
| ATEL2 | Atelophragma elegans (Hook.) Rydb. | Astragalus eucosmus | Fabaceae
|
| ATHA2 | Atelophragma harringtonii Rydb. | Astragalus robbinsii var. harringtonii | Fabaceae
|
| ATMO | Atenia montana (Blank.) Rydb. | Perideridia gairdneri ssp. borealis | Apiaceae
|
| ATLU | Ateramnus lucidus (Sw.) Rothm. | Gymnanthes lucida | Euphorbiaceae
|
| ATHYC | Athalamia hyalina (Sommerf.) S. Hatt. var. californica (M. Howe) R. M. Schust. | | Cleveaceae
|
| ATHYH | Athalamia hyalina (Sommerf.) S. Hatt. var. hyalina | | Cleveaceae
|
| ATHY2 | Athalamia hyalina (Sommerf.) S. Hatt. | | Cleveaceae
|
| ATPY2 | Athalamia pygmaea R. M. Schust. | | Cleveaceae
|
| ATHAL | Athalamia Falc. | | Cleveaceae
|
| ATEP | Athelia epiphylla Pers. | | Atheliaceae
|
| ATPO5 | Athelia poeltii Julich | | Atheliaceae
|
| ATHEL | Athelia Pers. | athelia | Atheliaceae
|
| ATCU2 | Atheropogon curtipendulus (Michx.) Fourn. | Bouteloua curtipendula var. curtipendula | Poaceae
|
| ATRA | Atheropogon radicosus Fourn. | Bouteloua radicosa | Poaceae
|
| ATJA2 | Athyriopsis japonicum auct. non Thunb. | Deparia petersonii | Dryopteridaceae
|
| ATALA | Athyrium alpestre (Hoppe) Milde ssp. americanum (Butters) Lellinger | Athyrium americanum | Dryopteridaceae
|
| ATALA2 | Athyrium alpestre (Hoppe) Milde var. americanum Butters | Athyrium americanum | Dryopteridaceae
|
| ATALC | Athyrium alpestre (Hoppe) Milde var. cyclosorum (Rupr.) T. Moore | Athyrium filix-femina ssp. cyclosorum | Dryopteridaceae
|
| ATALG | Athyrium alpestre (Hoppe) Milde var. gaspense Fern. | Athyrium americanum | Dryopteridaceae
|
| ATAL4 | Athyrium alpestre (Hoppe) Milde | Athyrium americanum | Dryopteridaceae
|
| ATAM | Athyrium americanum (Butters) Maxon | alpine ladyfern | Dryopteridaceae
|
| ATANB | Athyrium angustum (Willd.) K. Presl var. boreale Jennings | Athyrium filix-femina ssp. cyclosorum | Dryopteridaceae
|
| ATANE | Athyrium angustum (Willd.) K. Presl var. elatius (Link) Butters | Athyrium filix-femina ssp. cyclosorum | Dryopteridaceae
|
| ATANR2 | Athyrium angustum (Willd.) K. Presl var. rubellum (Gilbert) Butters | Athyrium filix-femina ssp. angustum | Dryopteridaceae
|
| ATANS | Athyrium angustum (Willd.) K. Presl var. subtripinnatum Butters | Athyrium filix-femina ssp. angustum | Dryopteridaceae
|
| ATAN2 | Athyrium angustum (Willd.) K. Presl | Athyrium filix-femina ssp. angustum | Dryopteridaceae
|
| ATAS | Athyrium asplenioides (Michx.) A.A. Eat. | Athyrium filix-femina ssp. asplenioides | Dryopteridaceae
|
| ATBA | Athyrium baldwinii (Hbd.) C. Christens. | Athyrium microphyllum | Dryopteridaceae
|
| ATDIA2 | Athyrium distentifolium Tausch ex Opiz ssp. americanum (Butters) Hult�n | Athyrium americanum | Dryopteridaceae
|
| ATDIA3 | Athyrium distentifolium Tausch ex Opiz var. americanum (Butters) Boivin | Athyrium americanum | Dryopteridaceae
|
| ATES | Athyrium esculentum (Retz.) Copeland | Diplazium esculentum | Dryopteridaceae
|
| ATFE2 | Athyrium fenzlianum (Luerss.) O.& I. Deg. | Deparia fenzliana | Dryopteridaceae
|
| ATFIA | Athyrium filix-femina (L.) Roth ssp. angustum (Willd.) Clausen | subarctic ladyfern | Dryopteridaceae
|
| ATFIA2 | Athyrium filix-femina (L.) Roth ssp. asplenioides (Michx.) Hult�n | asplenium ladyfern | Dryopteridaceae
|
| ATFIC | Athyrium filix-femina (L.) Roth ssp. cyclosorum (Rupr.) C. Christens. | subarctic ladyfern | Dryopteridaceae
|
| ATFIA4 | Athyrium filix-femina (L.) Roth var. angustum (Willd.) Lawson | Athyrium filix-femina ssp. angustum | Dryopteridaceae
|
| ATFIA3 | Athyrium filix-femina (L.) Roth var. asplenioides (Michx.) Farw. | Athyrium filix-femina ssp. asplenioides | Dryopteridaceae
|
| ATFIC3 | Athyrium filix-femina (L.) Roth var. californicum Butters | Athyrium filix-femina ssp. cyclosorum | Dryopteridaceae
|
| ATFIC2 | Athyrium filix-femina (L.) Roth var. cyclosorum (Rupr.) Ledeb. | Athyrium filix-femina ssp. cyclosorum | Dryopteridaceae
|
| ATFIM | Athyrium filix-femina (L.) Roth var. michauxii (Spreng.) Farw. | Athyrium filix-femina ssp. angustum | Dryopteridaceae
|
| ATFIR | Athyrium filix-femina (L.) Roth var. rubellum Gilbert | Athyrium filix-femina ssp. angustum | Dryopteridaceae
|
| ATFIS | Athyrium filix-femina (L.) Roth var. sitchense (Rupr.) Ledeb. | Athyrium filix-femina ssp. cyclosorum | Dryopteridaceae
|
| ATFI | Athyrium filix-femina (L.) Roth | common ladyfern | Dryopteridaceae
|
| ATJA | Athyrium japonicum auct. non (Thunb.) Copeland | Deparia petersonii | Dryopteridaceae
|
| ATKA | Athyrium kaalaanum Copeland | Deparia kaalaana | Dryopteridaceae
|
| ATMI | Athyrium microphyllum (J. Sm.) Alston | akolea | Dryopteridaceae
|
| ATPO4 | Athyrium poiretianum (Gaud.) K. Presl | Athyrium microphyllum | Dryopteridaceae
|
| ATPY | Athyrium pycnocarpon (Spreng.) Tidestrom | Diplazium pycnocarpon | Dryopteridaceae
|
| ATSA3 | Athyrium sandwichianum K. Presl | Diplazium sandwichianum | Dryopteridaceae
|
| ATTH | Athyrium thelypterioides (Michx.) Desv. | Deparia acrostichoides | Dryopteridaceae
|
| ATHYR | Athyrium Roth | ladyfern | Dryopteridaceae
|
| ATPE2 | Athyrocarpus persicariifolius (Delile) Hemsl. | Commelina rufipes var. glabrata | Commelinaceae
|
| ATPUG | Athysanus pusillus (Hook.) Greene var. glabrior S. Wats. | Athysanus pusillus | Brassicaceae
|
| ATPU | Athysanus pusillus (Hook.) Greene | common sandweed | Brassicaceae
|
| ATUN | Athysanus unilateralis (M.E. Jones) Jepson | Heterodraba unilateralis | Brassicaceae
|
| ATHYS | Athysanus Greene | sandweed | Brassicaceae
|
| ATCO9 | Atractylocarpus costaricensis (C. M�ll.) Williams | Campylopodiella stenocarpa | Dicranaceae
|
| ATFL | Atractylocarpus flagellaceus (C. M�ll.) Williams | Campylopodiella stenocarpa | Dicranaceae
|
| ATST | Atractylocarpus stenocarpus (Wils. in Seem.) Zand. | Campylopodiella stenocarpa | Dicranaceae
|
| ATAM2 | Atragene americana Sims | Clematis occidentalis var. occidentalis | Ranunculaceae
|
| ATCO7 | Atragene columbiana Nutt. | Clematis columbiana var. columbiana | Ranunculaceae
|
| ATOC | Atragene occidentalis Hornem. | Clematis occidentalis var. occidentalis | Ranunculaceae
|
| ATPL | Atrichoseris platyphylla (Gray) Gray | parachute plant | Asteraceae
|
| ATRIC | Atrichoseris Gray | atrichoseris | Asteraceae
|
| ATAL6 | Atrichum altecristatum (Ren. & Card.) Smyth & Smyth | atrichum moss | Polytrichaceae
|
| ATANO | Atrichum androgynum (C. Mll.) Nyh. var. oerstedianum (C. M�ll.) Nyh. | Atrichum oerstedianum | Polytrichaceae
|
| ATANP | Atrichum angustatum (Brid.) Bruch & Schimp. in B.S.G. var. plurilamellatum (Jenn.) Frye in Grout | Atrichum angustatum | Polytrichaceae
|
| ATAN3 | Atrichum angustatum (Brid.) Bruch & Schimp. in B.S.G. | atrichum moss | Polytrichaceae
|
| ATCRM | Atrichum crispum (James) Sull. var. molle (Holz.) Frye in Grout | Atrichum tenellum | Polytrichaceae
|
| ATCR | Atrichum crispum (James) Sull. | atrichum moss | Polytrichaceae
|
| ATCY | Atrichum cylindricum (Willd. in Web.) G. L. Sm. | cylindrical atrichum moss | Polytrichaceae
|
| ATFE3 | Atrichum fertile Nawasch. | Atrichum haussknechtii | Polytrichaceae
|
| ATHA4 | Atrichum haussknechtii Jur. & Milde | Haussknecht's atrichum moss | Polytrichaceae
|
| ATMA4 | Atrichum macmillanii (Holz.) Frye in Grout | Atrichum angustatum | Polytrichaceae
|
| ATOE | Atrichum oerstedianum (C. M�ll.) Mitt. | Oersted's atrichum moss | Polytrichaceae
|
| ATPA5 | Atrichum papillosum (Jenn.) Frye in Grout | Atrichum angustatum | Polytrichaceae
|
| ATPA6 | Atrichum paraphyllium Wareh. | Atrichum oerstedianum | Polytrichaceae
|
| ATRO3 | Atrichum rosulatum C. M�ll. & Kindb. in Mac. & Kindb. | Atrichum selwynii | Polytrichaceae
|
| ATSEA | Atrichum selwynii Aust. var. altecristatum (Ren. & Card.) Nyh. | Atrichum altecristatum | Polytrichaceae
|
| ATSE3 | Atrichum selwynii Aust. | Selwyn's atrichum moss | Polytrichaceae
|
| ATTE70 | Atrichum tenellum (R�hl.) Bruch & Schimp. in B.S.G. | atrichum moss | Polytrichaceae
|
| ATUNA | Atrichum undulatum (Hedw.) P. Beauv. var. alleghaniense (Jenn.) Jenn. | Atrichum altecristatum | Polytrichaceae
|
| ATUNA2 | Atrichum undulatum (Hedw.) P. Beauv. var. altecristatum Ren. & Card. | Atrichum altecristatum | Polytrichaceae
|
| ATUNA3 | Atrichum undulatum (Hedw.) P. Beauv. var. attenuatum Bruch & Schimp. in B.S.G. | Atrichum cylindricum | Polytrichaceae
|
| ATUNG | Atrichum undulatum (Hedw.) P. Beauv. var. gracilisetum Besch. | Atrichum haussknechtii | Polytrichaceae
|
| ATUNH | Atrichum undulatum (Hedw.) P. Beauv. var. haussknechtii (Jur. & Milde) Frye in Grout | Atrichum haussknechtii | Polytrichaceae
|
| ATUNO | Atrichum undulatum (Hedw.) P. Beauv. var. oerstedianum (C. M�ll.) Crum | Atrichum oerstedianum | Polytrichaceae
|
| ATUNS | Atrichum undulatum (Hedw.) P. Beauv. var. selwynii (Aust.) Frye in Grout | Atrichum selwynii | Polytrichaceae
|
| ATUN2 | Atrichum undulatum (Hedw.) P. Beauv. | undulate atrichum moss | Polytrichaceae
|
| ATXA | Atrichum xanthopelma (C. M�ll.) Jaeg. | Atrichum angustatum | Polytrichaceae
|
| ATRIC2 | Atrichum P. Beauv. | atrichum moss | Polytrichaceae
|
| ATAC2 | Atriplex acadiensis Taschereau | maritime saltbush | Chenopodiaceae
|
| ATACA | Atriplex acanthocarpa (Torr.) S. Wats. ssp. acanthocarpa | tubercled saltbush | Chenopodiaceae
|
| ATACC | Atriplex acanthocarpa (Torr.) S. Wats. ssp. coahuilensis Henrickson | tubercled saltbush | Chenopodiaceae
|
| ATACC2 | Atriplex acanthocarpa (Torr.) S. Wats. var. coahuilensis (Henrickson) Welsh & Crompton | Atriplex acanthocarpa ssp. coahuilensis | Chenopodiaceae
|
| ATACC3 | Atriplex acanthocarpa (Torr.) S. Wats. var. cuneata (A. Nels.) M.E. Jones | Atriplex cuneata ssp. cuneata | Chenopodiaceae
|
| ATAC | Atriplex acanthocarpa (Torr.) S. Wats. | tubercled saltbush | Chenopodiaceae
|
| ATAL | Atriplex alaskensis S. Wats. | Alaska orache | Chenopodiaceae
|
| ATAP | Atriplex �aptera A. Nels. (pro sp.) | moundscale | Chenopodiaceae
|