| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| ARGYT | Argythamnia P. Br. | silverbush | Euphorbiaceae
|
| ARFI | Ariocarpus fissuratus (Engelm.) K. Schum. | chautle livingrock | Cactaceae
|
| ARIOC | Ariocarpus Scheidw. | livingrock | Cactaceae
|
| ARAC7 | Arisaema acuminatum Small | Arisaema triphyllum ssp. pusillum | Araceae
|
| ARATS | Arisaema atrorubens (Ait.) Blume var. stewardsonii (Britt.) G.T. Stevens | Arisaema triphyllum ssp. stewardsonii | Araceae
|
| ARAT5 | Arisaema atrorubens (Ait.) Blume | Arisaema triphyllum ssp. triphyllum | Araceae
|
| ARDR3 | Arisaema dracontium (L.) Schott | green dragon | Araceae
|
| ARHE8 | Arisaema heterophyllum Blume | arisaema | Araceae
|
| ARJA3 | Arisaema japonicum Blume | Japanese arisaema | Araceae
|
| ARPU17 | Arisaema pusillum (Peck) Nash | Arisaema triphyllum ssp. pusillum | Araceae
|
| ARQU | Arisaema quinatum (Buckl.) Schott | Arisaema triphyllum ssp. quinatum | Araceae
|
| ARSP13 | Arisaema speciosum (Wallich) C. Martius | cobralily | Araceae
|
| ARST9 | Arisaema stewardsonii Britt. | Arisaema triphyllum ssp. stewardsonii | Araceae
|
| ARTO7 | Arisaema tortuosum (Wallich) Schott | arisaema | Araceae
|
| ARTRP | Arisaema triphyllum (L.) Schott ssp. pusillum (Peck) Huttleston | Jack in the pulpit | Araceae
|
| ARTRQ | Arisaema triphyllum (L.) Schott ssp. quinatum (Buckl.) Huttleston | Jack in the pulpit | Araceae
|
| ARTRS | Arisaema triphyllum (L.) Schott ssp. stewardsonii (Britt.) Huttleston | Jack in the pulpit | Araceae
|
| ARTRT3 | Arisaema triphyllum (L.) Schott ssp. triphyllum | Jack in the pulpit | Araceae
|
| ARTR | Arisaema triphyllum (L.) Schott | Jack in the pulpit | Araceae
|
| ARISA | Arisaema Mart. | Jack in the pulpit | Araceae
|
| ARGE2 | Aristea gerrardii Weim. | Gerrard's aristea | Iridaceae
|
| ARIST3 | Aristea Ait. | aristea | Iridaceae
|
| ARADA | Aristida adscensionis L. var. abortiva Beetle | Aristida adscensionis | Poaceae
|
| ARADM | Aristida adscensionis L. var. modesta Hack. | Aristida adscensionis | Poaceae
|
| ARAD | Aristida adscensionis L. | sixweeks threeawn | Poaceae
|
| ARAF | Aristida affinis (J.A. Schultes) Kunth | Aristida purpurascens var. purpurascens | Poaceae
|
| ARAF2 | Aristida affinis auct. non (J.A. Schultes) Kunth | Aristida palustris | Poaceae
|
| ARAM4 | Aristida americana L. | Bouteloua americana | Poaceae
|
| ARAR6 | Aristida arizonica Vasey | Arizona threeawn | Poaceae
|
| ARBA | Aristida barbata Fourn. | Aristida havardii | Poaceae
|
| ARBAC | Aristida basiramea Engelm. ex Vasey var. curtissii (Gray ex S. Wats. & Coult.) Shinners | Aristida dichotoma var. curtissii | Poaceae
|
| ARBA2 | Aristida basiramea Engelm. ex Vasey | forked threeawn | Poaceae
|
| ARBE7 | Aristida beyrichiana Trin. & Rupr. | Beyrich threeawn | Poaceae
|
| ARBR10 | Aristida brownii Warnock | Aristida purpurea var. wrightii | Poaceae
|
| ARCAC8 | Aristida californica Thurb. ex S. Wats. var. californica | California threeawn | Poaceae
|
| ARCAG | Aristida californica Thurb. ex S. Wats. var. glabrata Vasey | Santa Rita threeawn | Poaceae
|
| ARCA9 | Aristida californica Thurb. ex S. Wats. | California threeawn | Poaceae
|
| ARCH4 | Aristida chaseae A.S. Hitchc. | Chase's threeawn | Poaceae
|
| ARCO10 | Aristida cognata Trin. & Rupr. | spreading threeawn | Poaceae
|
| ARCOC7 | Aristida condensata Chapman var. combsii (Scribn. & Ball) Henr. | Aristida condensata | Poaceae
|
| ARCO7 | Aristida condensata Chapman | piedmont threeawn | Poaceae
|
| ARCU3 | Aristida curtissii (Gray ex S. Wats. & Coult.) Nash | Aristida dichotoma var. curtissii | Poaceae
|
| ARDE3 | Aristida desmantha Trin. & Rupr. | curly threeawn | Poaceae
|
| ARDIC | Aristida dichotoma Michx. var. curtissii Gray ex S. Wats. & Coult. | Curtis' threeawn | Poaceae
|
| ARDID | Aristida dichotoma Michx. var. dichotoma | churchmouse threeawn | Poaceae
|
| ARDI4 | Aristida dichotoma Michx. | churchmouse threeawn | Poaceae
|
| ARDI14 | Aristida dissita I.M. Johnston | Aristida pansa | Poaceae
|
| ARDI5 | Aristida divaricata Humb. & Bonpl. ex Willd. | poverty threeawn | Poaceae
|
| ARFA4 | Aristida fasciculata Torr. | Aristida adscensionis | Poaceae
|
| ARFE4 | Aristida fendleriana Steud. | Aristida purpurea var. fendleriana | Poaceae
|
| ARFL | Aristida floridana (Chapman) Vasey | Key West threeawn | Poaceae
|
| ARGE3 | Aristida geniculata Raf. | Aristida longispica var. geniculata | Poaceae
|
| ARGL6 | Aristida glabrata (Vasey) A.S. Hitchc. | Aristida californica var. glabrata | Poaceae
|
| ARGL7 | Aristida glauca (Nees) Walp. | Aristida purpurea var. nealleyi | Poaceae
|
| ARGR13 | Aristida gracilis Ell. | Aristida longispica var. longispica | Poaceae
|
| ARGY4 | Aristida gypsophila Beetle | gypsum threeawn | Poaceae
|
| ARGY | Aristida gyrans Chapman | corkscrew threeawn | Poaceae
|
| ARHA | Aristida hamulosa Henr. | Aristida ternipes var. gentilis | Poaceae
|
| ARHA3 | Aristida havardii Vasey | Havard's threeawn | Poaceae
|
| ARIN8 | Aristida intermedia Scribn. & Ball | Aristida longispica var. geniculata | Poaceae
|
| ARLAM | Aristida lanosa Muhl. ex Ell. var. macera Fern. & Grisc. | Aristida lanosa | Poaceae
|
| ARLA6 | Aristida lanosa Muhl. ex Ell. | woollysheath threeawn | Poaceae
|
| ARLOR2 | Aristida longiseta Steud. var. rariflora A.S. Hitchc. | Aristida purpurea var. longiseta | Poaceae
|
| ARLOR | Aristida longiseta Steud. var. robusta Merr. | Aristida purpurea var. longiseta | Poaceae
|
| ARLO3 | Aristida longiseta Steud. | Aristida purpurea var. longiseta | Poaceae
|
| ARLOG | Aristida longispica Poir. var. geniculata (Raf.) Fern. | slimspike threeawn | Poaceae
|
| ARLOL2 | Aristida longispica Poir. var. longispica | slimspike threeawn | Poaceae
|
| ARLO2 | Aristida longispica Poir. | slimspike threeawn | Poaceae
|
| ARMO3 | Aristida mohrii Nash | Mohr's threeawn | Poaceae
|
| ARNE9 | Aristida nealleyi (Vasey) Vasey | Aristida purpurea var. nealleyi | Poaceae
|
| ARNE8 | Aristida necopina Shinners | Aristida longispica var. geniculata | Poaceae
|
| AROL | Aristida oligantha Michx. | prairie threeawn | Poaceae
|
| AROR2 | Aristida orcuttiana Vasey | Aristida schiedeana var. orcuttiana | Poaceae
|
| ARPA26 | Aristida palustris (Chapman) Vasey | longleaf threeawn | Poaceae
|
| ARPAD | Aristida pansa Woot. & Standl. var. dissita (I.M. Johnston) Beetle | Aristida pansa | Poaceae
|
| ARPA9 | Aristida pansa Woot. & Standl. | Wooton's threeawn | Poaceae
|
| ARPA24 | Aristida parishii A.S. Hitchc. | Aristida purpurea var. parishii | Poaceae
|
| ARPA11 | Aristida patula Chapman ex Nash | tall threeawn | Poaceae
|
| ARPO3 | Aristida portoricensis Pilger | pelos del diablo | Poaceae
|
| ARPUM3 | Aristida purpurascens Poir. var. minor Vasey | Aristida purpurascens var. purpurascens | Poaceae
|
| ARPUP4 | Aristida purpurascens Poir. var. purpurascens | arrowfeather threeawn | Poaceae
|
| ARPUT | Aristida purpurascens Poir. var. tenuispica (A.S. Hitchc.) Allred | arrowfeather threeawn | Poaceae
|
| ARPUV | Aristida purpurascens Poir. var. virgata (Trin.) Allred | arrowfeather threeawn | Poaceae
|
| ARPU8 | Aristida purpurascens Poir. | arrowfeather threeawn | Poaceae
|
| ARPUF | Aristida purpurea Nutt. var. fendleriana (Steud.) Vasey | Fendler's threeawn | Poaceae
|
| ARPUG2 | Aristida purpurea Nutt. var. glauca (Nees) A. & N. Holmgren | Aristida purpurea var. nealleyi | Poaceae
|
| ARPUL3 | Aristida purpurea Nutt. var. laxiflora Merr. | Aristida purpurea var. purpurea | Poaceae
|
| ARPUL | Aristida purpurea Nutt. var. longiseta (Steud.) Vasey | Fendler threeawn | Poaceae
|
| ARPUN | Aristida purpurea Nutt. var. nealleyi (Vasey) Allred | blue threeawn | Poaceae
|
| ARPUP5 | Aristida purpurea Nutt. var. parishii (A.S. Hitchc.) Allred | Parish's threeawn | Poaceae
|
| ARPUP9 | Aristida purpurea Nutt. var. perplexa Allred & Vald�s-Reyna | purple threeawn | Poaceae
|
| ARPUP6 | Aristida purpurea Nutt. var. purpurea | purple threeawn | Poaceae
|
| ARPUR3 | Aristida purpurea Nutt. var. robusta (Merr.) Piper | Aristida purpurea var. longiseta | Poaceae
|
| ARPUW | Aristida purpurea Nutt. var. wrightii (Nash) Allred | Wright's threeawn | Poaceae
|
| ARPU9 | Aristida purpurea Nutt. | purple threeawn | Poaceae
|
| ARRAC | Aristida ramosissima Engelm. ex Gray var. chaseana Henr. | Aristida oligantha | Poaceae
|
| ARRA2 | Aristida ramosissima Engelm. ex Gray | s-curve threeawn | Poaceae
|
| ARRE4 | Aristida refracta Griseb. | islandthicket threeawn | Poaceae
|
| ARRE9 | Aristida reverchonii Vasey | Aristida purpurea var. nealleyi | Poaceae
|
| ARRH | Aristida rhizomophora Swallen | Florida threeawn | Poaceae
|
| ARRO3 | Aristida roemeriana Scheele | Aristida purpurea var. purpurea | Poaceae
|