| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| ASPAP7 | Astragalus pattersonii Gray var. praelongus (Sheldon) M.E. Jones | Astragalus praelongus var. praelongus | Fabaceae
|
| ASPA14 | Astragalus pattersonii Gray | Patterson's milkvetch | Fabaceae
|
| ASPA15 | Astragalus pauperculus Greene | depauperate milkvetch | Fabaceae
|
| ASPA16 | Astragalus paysonii (Rydb.) Barneby | Payson's milkvetch | Fabaceae
|
| ASPE12 | Astragalus peabodianus M.E. Jones | Astragalus pubentissimus | Fabaceae
|
| ASPE4 | Astragalus peckii Piper | Peck's milkvetch | Fabaceae
|
| ASPEP | Astragalus pectinatus (Hook.) Dougl. ex G. Don var. platyphyllus M.E. Jones | Astragalus nelsonianus | Fabaceae
|
| ASPE5 | Astragalus pectinatus (Hook.) Dougl. ex G. Don | narrowleaf milkvetch | Fabaceae
|
| ASPE11 | Astragalus peirsonii Munz & McBurney | Astragalus magdalenae var. peirsonii | Fabaceae
|
| ASPE6 | Astragalus perianus Barneby | Rydberg's milkvetch | Fabaceae
|
| ASPH | Astragalus phoenix Barneby | Ash Meadows milkvetch | Fabaceae
|
| ASPI3 | Astragalus pictiformis Barneby | Guadalupe milkvetch | Fabaceae
|
| ASPIA | Astragalus pinonis M.E. Jones var. atwoodii (Welsh & Thorne) Barneby & Isely | Duane's milkvetch | Fabaceae
|
| ASPIP4 | Astragalus pinonis M.E. Jones var. pinonis | pinyon milkvetch | Fabaceae
|
| ASPI4 | Astragalus pinonis M.E. Jones | pinyon milkvetch | Fabaceae
|
| ASPI6 | Astragalus piscator Barneby & Welsh | Fisher milkvetch | Fabaceae
|
| ASPI7 | Astragalus piutensis Barneby & Mabberley | Sevier milkvetch | Fabaceae
|
| ASPL2 | Astragalus plattensis Nutt. | Platte River milkvetch | Fabaceae
|
| ASPL3 | Astragalus platytropis Gray | broadkeel milkvetch | Fabaceae
|
| ASPL8 | Astragalus pleianthus (Shinners) Isely | Edwards Plateau milkvetch | Fabaceae
|
| ASPL9 | Astragalus plumbeus Barneby | Astragalus molybdenus | Fabaceae
|
| ASPO | Astragalus polaris Benth. | polar milkvetch | Fabaceae
|
| ASPO2 | Astragalus pomonensis M.E. Jones | Pomona milkvetch | Fabaceae
|
| ASPO3 | Astragalus porrectus S. Wats. | Lahontan milkvetch | Fabaceae
|
| ASPRE | Astragalus praelongus Sheldon var. ellisiae (Rydb.) Barneby | Ellis' stinking milkvetch | Fabaceae
|
| ASPRL | Astragalus praelongus Sheldon var. lonchopus Barneby | stinking milkvetch | Fabaceae
|
| ASPRP2 | Astragalus praelongus Sheldon var. praelongus | stinking milkvetch | Fabaceae
|
| ASPR5 | Astragalus praelongus Sheldon | stinking milkvetch | Fabaceae
|
| ASPRC2 | Astragalus preussii Gray var. cutleri Barneby | Cutler's milkvetch | Fabaceae
|
| ASPRL3 | Astragalus preussii Gray var. latus M.E. Jones | Astragalus preussii var. preussii | Fabaceae
|
| ASPRL2 | Astragalus preussii Gray var. laxiflorus Gray | Preuss' milkvetch | Fabaceae
|
| ASPRP3 | Astragalus preussii Gray var. preussii | Preuss' milkvetch | Fabaceae
|
| ASPR6 | Astragalus preussii Gray | Preuss' milkvetch | Fabaceae
|
| ASPR7 | Astragalus proimanthus Barneby | precocious milkvetch | Fabaceae
|
| ASPR8 | Astragalus proximus (Rydb.) Woot. & Standl. | Aztec milkvetch | Fabaceae
|
| ASPS | Astragalus pseudiodanthus Barneby | Tonopah milkvetch | Fabaceae
|
| ASPT2 | Astragalus pterocarpus S. Wats. | winged milkvetch | Fabaceae
|
| ASPUP2 | Astragalus pubentissimus Torr. & Gray var. peabodianus (M.E. Jones) Welsh | Astragalus pubentissimus | Fabaceae
|
| ASPU6 | Astragalus pubentissimus Torr. & Gray | Green River milkvetch | Fabaceae
|
| ASPUP5 | Astragalus pulsiferae Gray var. pulsiferae | Ames' milkvetch | Fabaceae
|
| ASPUS | Astragalus pulsiferae Gray var. suksdorfii (T.J. Howell) Barneby | Suksdorf's milkvetch | Fabaceae
|
| ASPU7 | Astragalus pulsiferae Gray | Ames' milkvetch | Fabaceae
|
| ASPUG | Astragalus puniceus Osterhout var. gertrudis (Greene) Barneby | Trinidad milkvetch | Fabaceae
|
| ASPUP6 | Astragalus puniceus Osterhout var. puniceus | Trinidad milkvetch | Fabaceae
|
| ASPU8 | Astragalus puniceus Osterhout | Trinidad milkvetch | Fabaceae
|
| ASPUC | Astragalus purshii Dougl. ex Hook. var. concinnus Barneby | woollypod milkvetch | Fabaceae
|
| ASPUG2 | Astragalus purshii Dougl. ex Hook. var. glareosus (Dougl. ex Hook.) Barneby | woollypod milkvetch | Fabaceae
|
| ASPUI | Astragalus purshii Dougl. ex Hook. var. interior M.E. Jones | Astragalus purshii var. purshii | Fabaceae
|
| ASPUL | Astragalus purshii Dougl. ex Hook. var. lagopinus (Rydb.) Barneby | woollypod milkvetch | Fabaceae
|
| ASPUL2 | Astragalus purshii Dougl. ex Hook. var. lectulus (S. Wats.) M.E. Jones | woollypod milkvetch | Fabaceae
|
| ASPUL3 | Astragalus purshii Dougl. ex Hook. var. longilobus M.E. Jones | Astragalus purshii var. tinctus | Fabaceae
|
| ASPUO | Astragalus purshii Dougl. ex Hook. var. ophiogenes (Barneby) Barneby | Snake River milkvetch | Fabaceae
|
| ASPUP | Astragalus purshii Dougl. ex Hook. var. pumilio Barneby | woollypod milkvetch | Fabaceae
|
| ASPUP7 | Astragalus purshii Dougl. ex Hook. var. purshii | woollypod milkvetch | Fabaceae
|
| ASPUT | Astragalus purshii Dougl. ex Hook. var. tinctus M.E. Jones | woollypod milkvetch | Fabaceae
|
| ASPU9 | Astragalus purshii Dougl. ex Hook. | woollypod milkvetch | Fabaceae
|
| ASPYL | Astragalus pycnostachyus Gray var. lanosissimus (Rydb.) Munz & McBurney ex Munz | marsh milkvetch | Fabaceae
|
| ASPYP | Astragalus pycnostachyus Gray var. pycnostachyus | marsh milkvetch | Fabaceae
|
| ASPY | Astragalus pycnostachyus Gray | marsh milkvetch | Fabaceae
|
| ASRAL | Astragalus racemosus Pursh var. longisetus M.E. Jones | cream milkvetch | Fabaceae
|
| ASRAR2 | Astragalus racemosus Pursh var. racemosus | cream milkvetch | Fabaceae
|
| ASRAT | Astragalus racemosus Pursh var. treleasei C.L. Porter | Trelease's milkvetch | Fabaceae
|
| ASRA2 | Astragalus racemosus Pursh | cream milkvetch | Fabaceae
|
| ASRA3 | Astragalus rafaelensis M.E. Jones | San Rafael milkvetch | Fabaceae
|
| ASRAJ | Astragalus rattanii Gray var. jepsonianus Barneby | Jepson's milkvetch | Fabaceae
|
| ASRAR3 | Astragalus rattanii Gray var. rattanii | Rattan's milkvetch | Fabaceae
|
| ASRA4 | Astragalus rattanii Gray | Rattan's milkvetch | Fabaceae
|
| ASRA5 | Astragalus ravenii Barneby | Raven's milkvetch | Fabaceae
|
| ASRE11 | Astragalus recedens (Greene ex Rydb.) C.L. Porter | Astragalus praelongus var. praelongus | Fabaceae
|
| ASRE2 | Astragalus recurvus Greene | recurved milkvetch | Fabaceae
|
| ASRE3 | Astragalus reflexus Torr. & Gray | drooping milkvetch | Fabaceae
|
| ASRE4 | Astragalus remotus (M.E. Jones) Barneby | Spring Mountain milkvetch | Fabaceae
|
| ASRE6 | Astragalus reventiformis (Rydb.) Barneby | Yakima milkvetch | Fabaceae
|
| ASREC2 | Astragalus reventus Gray var. canbyi M.E. Jones | Astragalus reventiformis | Fabaceae
|
| ASREC | Astragalus reventus Gray var. conjunctus (S. Wats.) M.E. Jones | Astragalus conjunctus var. conjunctus | Fabaceae
|
| ASREO | Astragalus reventus Gray var. oxytropidoides (M.E. Jones) C.L. Hitchc. | Astragalus hoodianus | Fabaceae
|
| ASRES | Astragalus reventus Gray var. sheldonii (Rydb.) C.L. Hitchc. | Astragalus sheldonii | Fabaceae
|
| ASRE5 | Astragalus reventus Gray | Blue Mountain milkvetch | Fabaceae
|
| ASRI4 | Astragalus richardsonii Sheldon | Astragalus australis | Fabaceae
|
| ASRI | Astragalus riparius Barneby | woodyroot milkvetch | Fabaceae
|
| ASRI2 | Astragalus ripleyi Barneby | Ripley's milkvetch | Fabaceae
|
| ASROH2 | Astragalus robbinsii (Oakes) Gray ssp. harringtonii (Rydb.) Hult�n | Astragalus robbinsii var. harringtonii | Fabaceae
|
| ASROA | Astragalus robbinsii (Oakes) Gray var. alpiniformis (Rydb.) Barneby ex C.L. Hitchc. | Robbins' milkvetch | Fabaceae
|
| ASROB | Astragalus robbinsii (Oakes) Gray var. blakei (Egglest.) Barneby | Astragalus robbinsii var. minor | Fabaceae
|
| ASROH | Astragalus robbinsii (Oakes) Gray var. harringtonii (Rydb.) Barneby | Harold's milkvetch | Fabaceae
|
| ASROJ | Astragalus robbinsii (Oakes) Gray var. jesupii Egglest. & Sheldon | Jesup's milkvetch | Fabaceae
|
| ASROM | Astragalus robbinsii (Oakes) Gray var. minor (Hook.) Barneby | Robbins' milkvetch | Fabaceae
|
| ASROO | Astragalus robbinsii (Oakes) Gray var. occidentalis S. Wats. | western milkvetch | Fabaceae
|
| ASROR | Astragalus robbinsii (Oakes) Gray var. robbinsii | Robbins' milkvetch | Fabaceae
|
| ASRO | Astragalus robbinsii (Oakes) Gray | Robbins' milkvetch | Fabaceae
|
| ASRU4 | Astragalus rusbyi Greene | Rusby's milkvetch | Fabaceae
|
| ASSA2 | Astragalus sabulonum Gray | gravel milkvetch | Fabaceae
|
| ASSA3 | Astragalus sabulosus M.E. Jones | Cisco milkvetch | Fabaceae
|
| ASSA17 | Astragalus salinus T.J. Howell | Astragalus lentiginosus var. salinus | Fabaceae
|
| ASSA4 | Astragalus salmonis M.E. Jones | Trout Creek milkvetch | Fabaceae
|
| ASSA16 | Astragalus sanctae-fidei Tidestrom | Astragalus feensis | Fabaceae
|
| ASSA5 | Astragalus saurinus Barneby | Dinosaur milkvetch | Fabaceae
|
| ASSC4 | Astragalus scaphoides (M.E. Jones) Rydb. | Bitterroot milkvetch | Fabaceae
|
| ASSC5 | Astragalus schmolliae C.L. Porter | Schmoll's milkvetch | Fabaceae
|
| ASSC6 | Astragalus sclerocarpus Gray | woodypod milkvetch | Fabaceae
|
| ASSC7 | Astragalus scopulorum Porter | Rocky Mountain milkvetch | Fabaceae
|