| ID | Symbol | Scientific | Common | Family |
| 508 | ACAMP | Acamptopappus (Gray) Gray | goldenhead | Asteraceae |
| 509 | ACSH | Acamptopappus shockleyi Gray | Shockley's goldenhead | Asteraceae |
| 510 | ACSP | Acamptopappus sphaerocephalus (Harvey & Gray ex Gray) Gray | rayless goldenhead | Asteraceae |
| 511 | ACSPH | Acamptopappus sphaerocephalus (Harvey & Gray ex Gray) Gray var. hirtellus Blake | rayless goldenhead | Asteraceae |
| 512 | ACSPS2 | Acamptopappus sphaerocephalus (Harvey & Gray ex Gray) Gray var. sphaerocephalus | rayless goldenhead | Asteraceae |
| 513 | APSP2 | Aplopappus sphaerocephalus Harvey & Gray ex Gray | Acamptopappus sphaerocephalus var. sphaerocephalus | Asteraceae |
| 528 | ACANT3 | Acanthospermum Schrank | starburr | Asteraceae |
| 529 | ACAU2 | Acanthospermum australe (Loefl.) Kuntze | Paraguayan starburr | Asteraceae |
| 530 | ACXA | Acanthospermum xanthioides DC. | Acanthospermum australe | Asteraceae |
| 531 | MEAU | Melampodium australe Loefl. | Acanthospermum australe | Asteraceae |
| 532 | ACHI | Acanthospermum hispidum DC. | hispid starburr | Asteraceae |
| 533 | ACHU | Acanthospermum humile (Sw.) DC. | low starburr | Asteraceae |
| 534 | MEHU5 | Melampodium humile Sw. | Acanthospermum humile | Asteraceae |
| 781 | ACHIL | Achillea L. | yarrow | Asteraceae |
| 782 | ACAE2 | Achillea aegyptiaca L. | | Asteraceae |
| 783 | ACTA3 | Achillea taygetea Boiss. & Heldr. | Achillea aegyptiaca | Asteraceae |
| 784 | ACAG | Achillea ageratifolia (Sibth. & Smith) Boiss. | yarrow | Asteraceae |
| 785 | ACAG3 | Achillea ageratum L. | sweet-Nancy | Asteraceae |
| 786 | ACAL17 | Achillea alpina L. | Chinese yarrow | Asteraceae |
| 787 | ACBI6 | Achillea biserrata M. Bieb. | | Asteraceae |
| 788 | ACCA29 | Achillea cartilaginea Ledeb. ex Rchb. | | Asteraceae |
| 789 | ACCH6 | Achillea chrysocoma Friv. | | Asteraceae |
| 790 | ACCL3 | Achillea clavennae L. | | Asteraceae |
| 791 | ACCL4 | Achillea clusiana Tausch | | Asteraceae |
| 792 | ACCL5 | Achillea clypeolata Sm. | | Asteraceae |
| 793 | ACCO19 | Achillea collina Becker ex Rchb. | | Asteraceae |
| 794 | ACCO20 | Achillea conferta DC. | | Asteraceae |
| 795 | ACCR3 | Achillea crithmifolia Waldst. & Kit. | | Asteraceae |
| 796 | ACDI6 | Achillea distans Waldst. & Kit. ex Willd. | Alps yarrow | Asteraceae |
| 797 | ACDE10 | Achillea dentifera DC. | Achillea distans | Asteraceae |
| 798 | ACDIT | Achillea distans Waldst. & Kit. ex Willd. ssp. tanacetifolia Janch. | | Asteraceae |
| 799 | ACTA2 | Achillea tanacetifolia All. | Achillea distans ssp. tanacetifolia | Asteraceae |
| 800 | ACER7 | Achillea erba-rotta All. | | Asteraceae |
| 801 | ACERR | Achillea erba-rotta All. ssp. rupestris (Porta) I. Richardson | | Asteraceae |
| 802 | ACRU13 | Achillea rupestris Porta | Achillea erba-rotta ssp. rupestris | Asteraceae |
| 803 | ACFI | Achillea filipendulina Lam. | fernleaf yarrow | Asteraceae |
| 804 | ACGR12 | Achillea grandifolia Friv. | | Asteraceae |
| 805 | ACIM6 | Achillea impatiens L. | | Asteraceae |
| 806 | ACLI2 | Achillea ligustica All. | Ligurian yarrow | Asteraceae |
| 807 | ACLI7 | Achillea lingulata Waldst. & Kit. | | Asteraceae |
| 808 | ACMA15 | Achillea macrocephala Rupr. | | Asteraceae |
| 809 | ACPTM | Achillea ptarmica L. ssp. macrocephala (Rupr.) Heimerl | Achillea macrocephala | Asteraceae |
| 810 | ACMA13 | Achillea macrophylla L. | | Asteraceae |
| 811 | ACMI2 | Achillea millefolium L. | common yarrow | Asteraceae |
| 812 | ACMA14 | Achillea magna auct. | Achillea millefolium | Asteraceae |
| 813 | ACMIA | Achillea millefolium L. var. alpicola (Rydb.) Garrett | common yarrow | Asteraceae |
| 814 | ACAL11 | Achillea alpicola (Rydb.) Rydb. | Achillea millefolium var. alpicola | Asteraceae |
| 815 | ACFU | Achillea fusca Rydb. | Achillea millefolium var. alpicola | Asteraceae |
| 816 | ACLAA | Achillea lanulosa Nutt. ssp. alpicola (Rydb.) Keck | Achillea millefolium var. alpicola | Asteraceae |
| 817 | ACLAA2 | Achillea lanulosa Nutt. var. alpicola Rydb. | Achillea millefolium var. alpicola | Asteraceae |
| 818 | ACMIF | Achillea millefolium L. var. fusca (Rydb.) G.N. Jones | Achillea millefolium var. alpicola | Asteraceae |
| 819 | ACSU3 | Achillea subalpina Greene | Achillea millefolium var. alpicola | Asteraceae |
| 820 | ACMIA2 | Achillea millefolium L. var. arenicola (Heller) Nobs | common yarrow | Asteraceae |
| 821 | ACAR6 | Achillea arenicola Heller | Achillea millefolium var. arenicola | Asteraceae |
| 822 | ACBOA | Achillea borealis Bong. ssp. arenicola (Heller) Keck | Achillea millefolium var. arenicola | Asteraceae |
| 823 | ACBOA2 | Achillea borealis Bong. var. arenicola (Heller) J.T. Howell | Achillea millefolium var. arenicola | Asteraceae |
| 824 | ACMIM4 | Achillea millefolium L. var. maritima Jepson | Achillea millefolium var. arenicola | Asteraceae |
| 825 | ACMIB | Achillea millefolium L. var. borealis (Bong.) Farw. | boreal yarrow | Asteraceae |
| 826 | ACBO | Achillea borealis Bong. | Achillea millefolium var. borealis | Asteraceae |
| 827 | ACBOT | Achillea borealis Bong. ssp. typica Keck | Achillea millefolium var. borealis | Asteraceae |
| 828 | ACMIA3 | Achillea millefolium L. ssp. atrotegula Boivin | Achillea millefolium var. borealis | Asteraceae |
| 829 | ACMIB2 | Achillea millefolium L. ssp. borealis (Bong.) Breitung | Achillea millefolium var. borealis | Asteraceae |
| 830 | ACMIF2 | Achillea millefolium L. var. fulva Boivin | Achillea millefolium var. borealis | Asteraceae |
| 831 | ACMIP3 | Achillea millefolium L. var. parviligula Boivin | Achillea millefolium var. borealis | Asteraceae |
| 832 | ACMIP4 | Achillea millefolium L. var. parvula Boivin | Achillea millefolium var. borealis | Asteraceae |
| 833 | ACMIC | Achillea millefolium L. var. californica (Pollard) Jepson | California yarrow | Asteraceae |
| 834 | ACBOC | Achillea borealis Bong. ssp. californica (Pollard) Keck | Achillea millefolium var. californica | Asteraceae |
| 835 | ACBOC2 | Achillea borealis Bong. var. californica (Pollard) J.T. Howell | Achillea millefolium var. californica | Asteraceae |
| 836 | ACCA7 | Achillea californica Pollard | Achillea millefolium var. californica | Asteraceae |
| 837 | ACMIG | Achillea millefolium L. var. gigantea (Pollard) Nobs | giant yarrow | Asteraceae |
| 838 | ACGI2 | Achillea gigantea Pollard | Achillea millefolium var. gigantea | Asteraceae |
| 839 | ACMIL2 | Achillea millefolium L. var. litoralis Ehrend. ex Nobs | coast yarrow | Asteraceae |
| 840 | ACMIM2 | Achillea millefolium L. var. millefolium | common yarrow | Asteraceae |
| 841 | ACMIN | Achillea millefolium L. var. nigrescens E. Mey. | common yarrow | Asteraceae |
| 842 | ACNI4 | Achillea nigrescens (E. Mey.) Rydb. | Achillea millefolium var. nigrescens | Asteraceae |
| 843 | ACMIO | Achillea millefolium L. var. occidentalis DC. | western yarrow | Asteraceae |
| 844 | ACAN7 | Achillea angustissima Rydb. | Achillea millefolium var. occidentalis | Asteraceae |
| 845 | ACAS2 | Achillea aspleniifolia auct. non Vent. [misapplied] | Achillea millefolium var. occidentalis | Asteraceae |
| 846 | ACER2 | Achillea eradiata Piper | Achillea millefolium var. occidentalis | Asteraceae |
| 847 | ACGR5 | Achillea gracilis Raf. | Achillea millefolium var. occidentalis | Asteraceae |
| 848 | ACLA5 | Achillea lanulosa Nutt. | Achillea millefolium var. occidentalis | Asteraceae |
| 849 | ACLAT | Achillea lanulosa Nutt. ssp. typica Keck | Achillea millefolium var. occidentalis | Asteraceae |
| 850 | ACLAA3 | Achillea lanulosa Nutt. var. arachnoidea Lunell | Achillea millefolium var. occidentalis | Asteraceae |
| 851 | ACLAE | Achillea lanulosa Nutt. var. eradiata (Piper) M.E. Peck | Achillea millefolium var. occidentalis | Asteraceae |
| 852 | ACLA3 | Achillea laxiflora Pollard & Cockerell | Achillea millefolium var. occidentalis | Asteraceae |
| 853 | ACMIL | Achillea millefolium L. ssp. lanulosa (Nutt.) Piper | Achillea millefolium var. occidentalis | Asteraceae |
| 854 | ACMIO2 | Achillea millefolium L. ssp. occidentalis (DC.) Hyl. | Achillea millefolium var. occidentalis | Asteraceae |
| 855 | ACMIP5 | Achillea millefolium L. ssp. pallidotegula Boivin | Achillea millefolium var. occidentalis | Asteraceae |
| 856 | ACMIA4 | Achillea millefolium L. var. aspleniifolia (Vent.) Farw. | Achillea millefolium var. occidentalis | Asteraceae |
| 857 | ACMIG2 | Achillea millefolium L. var. gracilis Raf. ex DC. | Achillea millefolium var. occidentalis | Asteraceae |
| 858 | ACMIL3 | Achillea millefolium L. var. lanulosa (Nutt.) Piper | Achillea millefolium var. occidentalis | Asteraceae |
| 859 | ACMIR | Achillea millefolium L. var. rosea (Desf.) Torr. & Gray | Achillea millefolium var. occidentalis | Asteraceae |
| 860 | ACMIR2 | Achillea millefolium L. var. russeolata Boivin | Achillea millefolium var. occidentalis | Asteraceae |
| 861 | ACOC | Achillea occidentalis (DC.) Raf. ex Rydb. | Achillea millefolium var. occidentalis | Asteraceae |
| 862 | ACRO4 | Achillea rosea Desf. | Achillea millefolium var. occidentalis | Asteraceae |
| 863 | ACTO3 | Achillea tomentosa Pursh, non L. | Achillea millefolium var. occidentalis | Asteraceae |
| 864 | ACMIP | Achillea millefolium L. var. pacifica (Rydb.) G.N. Jones | Pacific yarrow | Asteraceae |
| 865 | ACPA5 | Achillea pacifica Rydb. | Achillea millefolium var. pacifica | Asteraceae |
| 866 | ACMIP2 | Achillea millefolium L. var. puberula (Rydb.) Nobs | common yarrow | Asteraceae |
| 867 | ACPU2 | Achillea puberula Rydb. | Achillea millefolium var. puberula | Asteraceae |