| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| ASNE7 | Aster nebraskensis Britt. | Symphyotrichum praealtum var. nebraskense | Asteraceae
|
| ASNE | Aster nemoralis Ait. | Oclemena nemoralis | Asteraceae
|
| ASNE8 | Aster neomexicanus Woot. & Standl. | Symphyotrichum divaricatum | Asteraceae
|
| ASNO5 | Aster nobilis Burgess | Eurybia macrophylla | Asteraceae
|
| ASNO | Aster novae-angliae L. | Symphyotrichum novae-angliae | Asteraceae
|
| ASNOJ2 | Aster novi-belgii L. ssp. johannensis (Fern.) A.G. Jones | Symphyotrichum novi-belgii var. villicaule | Asteraceae
|
| ASNOC | Aster novi-belgii L. var. crenifolius (Fern.) J. Labrecque & L. Brouillet | Symphyotrichum novi-belgii var. crenifolium | Asteraceae
|
| ASNOE | Aster novi-belgii L. var. elodes (Torr. & Gray) Gray | Symphyotrichum novi-belgii var. elodes | Asteraceae
|
| ASNOJ | Aster novi-belgii L. var. johannensis (Fern.) A.G. Jones | Symphyotrichum novi-belgii var. villicaule | Asteraceae
|
| ASNOL | Aster novi-belgii L. var. litoreus Gray | Symphyotrichum praealtum var. praealtum | Asteraceae
|
| ASNOR | Aster novi-belgii L. var. rosaceus Rouss. | Symphyotrichum novi-belgii var. crenifolium | Asteraceae
|
| ASNOV | Aster novi-belgii L. var. villicaulis (Gray) Boivin | Symphyotrichum novi-belgii var. villicaule | Asteraceae
|
| ASNO2 | Aster novi-belgii L. | Symphyotrichum novi-belgii var. novi-belgii | Asteraceae
|
| ASOBA | Aster oblongifolius Nutt. var. angustatus Shinners | Symphyotrichum oblongifolium | Asteraceae
|
| ASOBO | Aster oblongifolius Nutt. var. orientis Shinners | Symphyotrichum oblongifolium | Asteraceae
|
| ASOBR | Aster oblongifolius Nutt. var. rigidulus Gray | Symphyotrichum oblongifolium | Asteraceae
|
| ASOB2 | Aster oblongifolius Nutt. | Symphyotrichum oblongifolium | Asteraceae
|
| ASOCD | Aster occidentalis (Nutt.) Torr. & Gray var. delectabilis (Hall) Ferris | Symphyotrichum spathulatum var. spathulatum | Asteraceae
|
| ASOCF | Aster occidentalis (Nutt.) Torr. & Gray var. fremontii (Torr. & Gray) A.G. Jones | Symphyotrichum spathulatum var. spathulatum | Asteraceae
|
| ASOCI | Aster occidentalis (Nutt.) Torr. & Gray var. intermedius Gray | Symphyotrichum spathulatum var. intermedium | Asteraceae
|
| ASOCP | Aster occidentalis (Nutt.) Torr. & Gray var. parishii (Gray) Ferris | Symphyotrichum spathulatum var. spathulatum | Asteraceae
|
| ASOCY | Aster occidentalis (Nutt.) Torr. & Gray var. yosemitanus (Gray) Cronq. | Symphyotrichum spathulatum var. yosemitanum | Asteraceae
|
| ASOC | Aster occidentalis (Nutt.) Torr. & Gray | Symphyotrichum spathulatum var. spathulatum | Asteraceae
|
| ASONG | Aster ontarionis Wieg. var. glabratus Semple | Symphyotrichum ontarione | Asteraceae
|
| ASON | Aster ontarionis Wieg. | Symphyotrichum ontarione | Asteraceae
|
| ASOOL2 | Aster oolentangiensis Riddell var. laevicaulis (Fern.) A.G. Jones | Symphyotrichum oolentangiense var. oolentangiense | Asteraceae
|
| ASOOP | Aster oolentangiensis Riddell var. poaceus (Burgess) A.G. Jones | Symphyotrichum oolentangiense var. poaceum | Asteraceae
|
| ASOO4 | Aster oolentangiensis Riddell | Symphyotrichum oolentangiense var. oolentangiense | Asteraceae
|
| ASOR3 | Aster orcuttii Vasey & Rose | Xylorhiza orcuttii | Asteraceae
|
| ASORC | Aster oregonensis (Nutt.) Cronq. ssp. californicus (Dur.) Keck | Sericocarpus oregonensis var. californicus | Asteraceae
|
| ASOR | Aster oregonensis (Nutt.) Cronq. | Sericocarpus oregonensis var. oregonensis | Asteraceae
|
| ASOR5 | Aster oregonum (Nutt.) Torr. & Gray | Symphyotrichum subspicatum var. subspicatum | Asteraceae
|
| ASOR4 | Aster oregonus auct. non (Nutt.) Torr. & Gray | Symphyotrichum eatonii | Asteraceae
|
| ASOS2 | Aster osterhoutii Rydb. | Symphyotrichum lanceolatum ssp. hesperium var. hesperium | Asteraceae
|
| ASPA19 | Aster palmeri Gray, non Ericameria palmeri (Gray) Hall | Xylothamia palmeri | Asteraceae
|
| ASPA25 | Aster paludicola Piper | Symphyotrichum spathulatum var. yosemitanum | Asteraceae
|
| ASPAH | Aster paludosus Ait. ssp. hemisphericus (Alexander) Cronq. | Eurybia hemispherica | Asteraceae
|
| ASPA2 | Aster paludosus Ait. | Eurybia paludosa | Asteraceae
|
| ASPAS | Aster paniculatus Lam. var. simplex (Willd.) Burgess | Symphyotrichum lanceolatum ssp. lanceolatum var. lanceolatum | Asteraceae
|
| ASPA35 | Aster paniculatus Lam., p.p. non P. Mill. | Symphyotrichum lanceolatum ssp. lanceolatum var. lanceolatum | Asteraceae
|
| ASPA3 | Aster pansus (Blake) Cronq. | Symphyotrichum ericoides var. pansum | Asteraceae
|
| ASPAT | Aster pantotrichus Blake var. thyrsoides (Gray) Blake | Symphyotrichum ontarione | Asteraceae
|
| ASPA23 | Aster pantotrichus Blake | Symphyotrichum ontarione | Asteraceae
|
| ASPA21 | Aster parryi Gray | Xylorhiza glabriuscula var. glabriuscula | Asteraceae
|
| ASPA4 | Aster parviceps (Burgess) Mackenzie & Bush | Symphyotrichum parviceps | Asteraceae
|
| ASPA20 | Aster parviflorus Gray, non Nees | Machaeranthera parviflora | Asteraceae
|
| ASPA30 | Aster parvulus Blake | Machaeranthera parviflora | Asteraceae
|
| ASPAF | Aster patens Ait. var. floridanus R.W. Long | Symphyotrichum fontinale | Asteraceae
|
| ASPAG | Aster patens Ait. var. georgianus (Alexander) Cronq. | Symphyotrichum georgianum | Asteraceae
|
| ASPAG2 | Aster patens Ait. var. gracilis Hook. | Symphyotrichum patens var. gracile | Asteraceae
|
| ASPAP | Aster patens Ait. var. patentissimus (Lindl. ex DC.) Torr. & Gray | Symphyotrichum patens var. patentissimum | Asteraceae
|
| ASPAP2 | Aster patens Ait. var. phlogifolius (Muhl. ex Willd.) Nees | Symphyotrichum phlogifolium | Asteraceae
|
| ASPA5 | Aster patens Ait. | Symphyotrichum patens var. patens | Asteraceae
|
| ASPA24 | Aster patentissimus Lindl. ex DC. | Symphyotrichum patens var. patentissimum | Asteraceae
|
| ASPA6 | Aster paternus Cronq. | Sericocarpus asteroides | Asteraceae
|
| ASPA26 | Aster pattersonii Gray | Machaeranthera bigelovii var. bigelovii | Asteraceae
|
| ASPA7 | Aster paucicapitatus (B.L. Robins.) B.L. Robins. | Eucephalus paucicapitatus | Asteraceae
|
| ASPA8 | Aster pauciflorus Nutt. | Almutaster pauciflorus | Asteraceae
|
| ASPE10 | Aster pedionomus Alexander | Eurybia hemispherica | Asteraceae
|
| ASPE2 | Aster peirsonii C.W. Sharsmith | Oreostemma peirsonii | Asteraceae
|
| ASPE9 | Aster pendulus Ait. | Symphyotrichum lateriflorum var. horizontale | Asteraceae
|
| ASPE3 | Aster perelegans A. Nels. & J.F. Macbr. | Eucephalus elegans | Asteraceae
|
| ASPH6 | Aster phlogifolius Muhl. ex Willd. | Symphyotrichum phlogifolium | Asteraceae
|
| ASPH4 | Aster phyllodes Rydb. | Symphyotrichum foliaceum var. canbyi | Asteraceae
|
| ASPH5 | Aster phyllolepis Torr. & Gray | Symphyotrichum pratense | Asteraceae
|
| ASPI8 | Aster pickettianus Suksdorf | Symphyotrichum laeve var. geyeri | Asteraceae
|
| ASPIP6 | Aster pilosus Willd. ssp. parviceps (Burgess) A.G. Jones | Symphyotrichum parviceps | Asteraceae
|
| ASPID3 | Aster pilosus Willd. var. demotus Blake | Symphyotrichum pilosum var. pringlei | Asteraceae
|
| ASPIP7 | Aster pilosus Willd. var. platyphyllus (Torr. & Gray) Blake | Symphyotrichum pilosum var. pilosum | Asteraceae
|
| ASPIP2 | Aster pilosus Willd. var. priceae (Britt.) Cronq. | Symphyotrichum priceae | Asteraceae
|
| ASPIP | Aster pilosus Willd. var. pringlei (Gray) Blake | Symphyotrichum pilosum var. pringlei | Asteraceae
|
| ASPIP5 | Aster pilosus Willd. var. pusillus (Gray) A.G. Jones | Symphyotrichum depauperatum | Asteraceae
|
| ASPI2 | Aster pilosus Willd. | Symphyotrichum pilosum var. pilosum | Asteraceae
|
| ASPI5 | Aster pinifolius Alexander, non Nees | Symphyotrichum kralii | Asteraceae
|
| ASPI10 | Aster pinnatifidus (Hook.) Kuntze | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | Asteraceae
|
| ASPL6 | Aster plumarius Burgess | Symphyotrichum cordifolium | Asteraceae
|
| ASPL7 | Aster plumosus Small | Symphyotrichum concolor | Asteraceae
|
| ASPO8 | Aster poaceus Burgess | Symphyotrichum oolentangiense var. poaceum | Asteraceae
|
| ASPO7 | Aster polycephalus Rydb. | Symphyotrichum ericoides var. ericoides | Asteraceae
|
| ASPO9 | Aster polyphyllus Willd., non Moench | Symphyotrichum pilosum var. pringlei | Asteraceae
|
| ASPO5 | Aster porteri Gray | Symphyotrichum porteri | Asteraceae
|
| ASPO6 | Aster potosinus Gray | Symphyotrichum potosinum | Asteraceae
|
| ASPRA | Aster praealtus Poir. var. angustior Wieg. | Symphyotrichum praealtum var. angustior | Asteraceae
|
| ASPRC | Aster praealtus Poir. var. caerulescens (DC.) A.G. Jones | Symphyotrichum praealtum var. praealtum | Asteraceae
|
| ASPRI | Aster praealtus Poir. var. imbricatior Wieg. | Symphyotrichum praealtum var. praealtum | Asteraceae
|
| ASPRN | Aster praealtus Poir. var. nebraskensis (Britt.) Wieg. | Symphyotrichum praealtum var. nebraskense | Asteraceae
|
| ASPRS | Aster praealtus Poir. var. subasper (Lindl.) Wieg. | Symphyotrichum praealtum var. subasperum | Asteraceae
|
| ASPRT | Aster praealtus Poir. var. texicola Wieg. | Symphyotrichum praealtum var. praealtum | Asteraceae
|
| ASPR2 | Aster praealtus Poir. | Symphyotrichum praealtum var. praealtum | Asteraceae
|
| ASPR3 | Aster pratensis Raf. | Symphyotrichum pratense | Asteraceae
|
| ASPR4 | Aster prenanthoides Muhl. ex Willd. | Symphyotrichum prenanthoides | Asteraceae
|
| ASPR17 | Aster priceae Britt. | Symphyotrichum priceae | Asteraceae
|
| ASPR13 | Aster pringlei (Gray) Britt. | Symphyotrichum pilosum var. pringlei | Asteraceae
|
| ASPR12 | Aster procumbens Houst. ex P. Mill. | Erigeron procumbens | Asteraceae
|
| ASPR11 | Aster proteus Burgess | Symphyotrichum undulatum | Asteraceae
|
| ASPTG | Aster ptarmicoides (Nees) Torr. & Gray var. georgianus Gray | Oligoneuron album | Asteraceae
|
| ASPTL | Aster ptarmicoides (Nees) Torr. & Gray var. lutescens (Lindl. ex DC.) Gray | Oligoneuron lutescens | Asteraceae
|
| ASPT4 | Aster ptarmicoides (Nees) Torr. & Gray | Oligoneuron album | Asteraceae
|
| ASPU4 | Aster pubentior Cronq. | Doellingeria umbellata var. pubens | Asteraceae
|
| ASPUE2 | Aster puniceus L. ssp. elliottii (Torr. & Gray) A.G. Jones | Symphyotrichum elliotii | Asteraceae
|
| ASPUF2 | Aster puniceus L. ssp. firmus (Nees) A.G. Jones | Symphyotrichum puniceum var. puniceum | Asteraceae
|