The statistics below compare all terminal taxa (e.g., subspecies and varieties along with those species that lack subspecies or varieties) treated in the 1st Edition (the 1973 manual) with those treated in the Second Edition of the Flora.
The 2nd Edition accounts for 5,545 taxa, a net increase of 1,130 (24.6%) relative to the 4,415 taxa treated in the 1st Edition. Of the 5,545 taxa treated, 5,335 are considered present within the Flora region, leaving 210 extralimital taxa (e.g., misapplications or geographically peripheral taxa); 5,085 taxa are given full treatment within key leads or descriptions while 452 are mentioned only in the commentary following family and genus descriptions.
The 24.6% increase relative to the 1st Edition is due to a number of factors. Foremost among these is the establishment, or detection, of additional exotic taxa within our area following publication of the 1st Edition. The number of exotic taxa treated has doubled, and accounts for ca. 69% of the net increase. The remaining 31% mainly stem from range extensions for native taxa, species recently published as new to science, and previously-published taxa resurrected through revisionary work. Increases in the number of families and genera have been driven largely by the establishment of new exotic taxa and revisionary work stemming from systematic studies. Molecular and phylogenetic methods have often led to narrower family and generic concepts; hence, more of them. Correspondingly, many taxa treated as infraspecies in the 1st Edition are now recognized at the rank of species, resulting in a net decrease of 4.6% in the number of infraspecies.
Nomenclatural changes between the two editions are numerous; only 58% of the 4,415 taxa included in the 1st Edition are treated in the 2nd Edition under the same names and taxonomic circumscriptions. Conversely, only 41% of the taxa treated in the 2nd Edition were also treated in the 1st Edition with unchanged names and circumscriptions; the remaining 59% represent the combined effect of nomenclatural changes and new additions to the flora.
Illustrations are provided for 4,373 (95%) of the 4,575 species given full treatment in the 2nd Edition, including 3,353 (99%) of the native species and 1,020 (85%) of the exotic species. Infraspecies are less frequently illustrated. The overall illustration rate for taxa given full treatment is 4,716 (93%) out of 5,085.
The largest families in the Flora are Asteraceae (681 terminal taxa), Poaceae (451), Fabaceae (352), Brassicaceae (278), Cyperaceae (274), and Rosaceae (248).
The largest genera are Carex (199 terminal taxa), Astragalus (125), Penstemon (84), Erigeron (73), Juncus (71), Eriogonum (66), Lomatium (62), and Castilleja (60).
| 1st Edition | 2nd Edition | Net Change | % Change | |
| Families | 129 | 159 | 30 | 23.3% |
| Genera | 826 | 1,141 | 315 | 38.1% |
| Species | 3,555 | 4,818 | 1,263 | 35.5% |
| Infraspecies | 1,393 | 1,329 | -64 | -4.6% |
| Native Taxa | 3,559 | 3,891 | 332 | 9.3% |
| Exotic Taxa | 722 | 1,444 | 722 | 100% |
| Total Taxa | 4,281 | 5,335 | 1,054 | 24.6% |
| Excluded Taxa | 134 | 210 | 76 | 56.7% |
Native taxa are those considered to be native to any part of the Flora region; the few taxa with both native and introduced populations are counted as native. Tallies include taxa mentioned only in the commentary following family and genus descriptions that nonetheless occur in the Flora region. Excluded taxa are those not known to be present in the Flora region that are nevertheless treated or mentioned in the 2nd Edition; excluded taxa are omitted from the other tallies.
| Families | Genera | Species | Infraspecies | Native Taxa | Exotic Taxa | Total Taxa | Excluded | |
| Lycophytes | 3 | 8 | 28 | 0 | 28 | 0 | 28 | 0 | Ferns | 17 | 31 | 105 | 26 | 110 | 4 | 114 | 6 | Gymnosperms | 3 | 11 | 41 | 16 | 41 | 8 | 49 | 4 | Nymphaeales | 2 | 4 | 8 | 1 | 5 | 3 | 8 | 0 | Piperales | 2 | 2 | 4 | 0 | 4 | 0 | 4 | 0 | Laurales | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | Ceratophyllales | 1 | 1 | 2 | 0 | 2 | 0 | 2 | 0 | Eudicots | 105 | 862 | 3,591 | 1,035 | 2,883 | 1,116 | 3,999 | 164 | Monocots | 25 | 221 | 1,038 | 251 | 818 | 312 | 1,130 | 36 | Total | 159 | 1,141 | 4,818 | 1,329 | 3,891 | 1,444 | 5,335 | 210 |
| Family | Genera | Species | Infraspecies | Terminal Taxa | Native | Exotic | Endemic | Excluded |
| Aspleniaceae | 1 | 4 | 3 | 5 | 4 | 1 | 0 | 1 |
| Athyriaceae | 1 | 2 | 3 | 3 | 3 | 0 | 0 | 0 |
| Blechnaceae | 2 | 2 | 0 | 2 | 2 | 0 | 0 | 0 |
| Cystopteridaceae | 2 | 5 | 0 | 5 | 5 | 0 | 0 | 0 |
| Dennstaedtiaceae | 1 | 1 | 2 | 2 | 2 | 0 | 0 | 0 |
| Dryopteridaceae | 2 | 17 | 1 | 17 | 17 | 0 | 0 | 0 |
| Equisetaceae | 1 | 13 | 4 | 14 | 14 | 0 | 0 | 0 |
| Hymenophyllaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Isoetaceae | 1 | 7 | 0 | 7 | 7 | 0 | 1 | 0 |
| Lycopodiaceae | 6 | 13 | 0 | 13 | 13 | 0 | 0 | 0 |
| Marsileaceae | 2 | 4 | 0 | 4 | 3 | 1 | 0 | 0 |
| Onocleaceae | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |
| Ophioglossaceae | 4 | 24 | 3 | 25 | 25 | 0 | 1 | 0 |
| Osmundaceae | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Polypodiaceae | 1 | 6 | 0 | 6 | 6 | 0 | 1 | 0 |
| Pteridaceae | 6 | 15 | 5 | 17 | 17 | 0 | 1 | 3 |
| Salviniaceae | 1 | 3 | 0 | 3 | 2 | 1 | 0 | 0 |
| Selaginellaceae | 1 | 8 | 0 | 8 | 8 | 0 | 1 | 0 |
| Thelypteridaceae | 3 | 3 | 0 | 3 | 3 | 0 | 0 | 0 |
| Woodsiaceae | 1 | 3 | 4 | 5 | 5 | 0 | 0 | 2 |
| Family | Genera | Species | Infraspecies | Terminal Taxa | Native | Exotic | Endemic | Excluded |
| Cupressaceae | 4 | 12 | 6 | 15 | 11 | 4 | 0 | 1 |
| Pinaceae | 6 | 27 | 10 | 32 | 29 | 3 | 3 | 3 |
| Taxaceae | 1 | 2 | 0 | 2 | 1 | 1 | 0 | 0 |
| Family | Genera | Species | Infraspecies | Terminal Taxa | Native | Exotic | Endemic | Excluded |
| Adoxaceae | 3 | 11 | 8 | 16 | 11 | 5 | 0 | 0 |
| Aizoaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Amaranthaceae | 25 | 87 | 16 | 91 | 42 | 49 | 2 | 11 |
| Anacardiaceae | 2 | 5 | 2 | 5 | 4 | 1 | 0 | 0 |
| Apiaceae | 40 | 145 | 12 | 147 | 122 | 25 | 41 | 3 |
| Apocynaceae | 3 | 9 | 0 | 9 | 7 | 2 | 0 | 0 |
| Aquifoliaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Araliaceae | 4 | 8 | 0 | 8 | 5 | 3 | 0 | 0 |
| Aristolochiaceae | 1 | 3 | 0 | 3 | 3 | 0 | 0 | 0 |
| Asteraceae | 161 | 613 | 185 | 681 | 508 | 173 | 61 | 14 |
| Balsaminaceae | 1 | 9 | 0 | 9 | 4 | 5 | 1 | 0 |
| Berberidaceae | 3 | 11 | 0 | 11 | 7 | 4 | 0 | 0 |
| Betulaceae | 3 | 15 | 6 | 17 | 13 | 4 | 0 | 0 |
| Bignoniaceae | 1 | 2 | 0 | 2 | 0 | 2 | 0 | 0 |
| Boraginaceae | 25 | 114 | 21 | 119 | 94 | 25 | 16 | 3 |
| Brassicaceae | 70 | 269 | 34 | 278 | 193 | 85 | 38 | 8 |
| Cabombaceae | 2 | 2 | 0 | 2 | 1 | 1 | 0 | 0 |
| Cactaceae | 3 | 6 | 2 | 6 | 6 | 0 | 1 | 2 |
| Campanulaceae | 11 | 32 | 2 | 32 | 23 | 9 | 1 | 1 |
| Cannabaceae | 3 | 4 | 3 | 6 | 2 | 4 | 0 | 0 |
| Caprifoliaceae | 2 | 19 | 6 | 21 | 13 | 8 | 1 | 1 |
| Caryophyllaceae | 35 | 131 | 50 | 144 | 80 | 64 | 8 | 0 |
| Celastraceae | 3 | 9 | 2 | 9 | 7 | 2 | 1 | 0 |
| Ceratophyllaceae | 1 | 2 | 0 | 2 | 2 | 0 | 0 | 0 |
| Cleomaceae | 3 | 5 | 2 | 5 | 5 | 0 | 0 | 0 |
| Convolvulaceae | 4 | 18 | 10 | 19 | 13 | 6 | 0 | 7 |
| Cornaceae | 1 | 5 | 0 | 5 | 5 | 0 | 0 | 0 |
| Crassulaceae | 3 | 23 | 3 | 24 | 18 | 6 | 4 | 0 |
| Crossosomataceae | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |
| Cucurbitaceae | 5 | 5 | 0 | 5 | 2 | 3 | 0 | 0 |
| Dipsacaceae | 2 | 2 | 0 | 2 | 0 | 2 | 0 | 0 |
| Droseraceae | 2 | 5 | 0 | 5 | 4 | 1 | 0 | 0 |
| Ehretiaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Elaeagnaceae | 2 | 5 | 0 | 5 | 3 | 2 | 0 | 0 |
| Elatinaceae | 2 | 5 | 0 | 5 | 5 | 0 | 0 | 0 |
| Ericaceae | 25 | 66 | 10 | 69 | 63 | 6 | 0 | 1 |
| Escalloniaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Euphorbiaceae | 4 | 29 | 1 | 29 | 7 | 22 | 0 | 0 |
| Fabaceae | 38 | 276 | 155 | 352 | 264 | 88 | 66 | 14 |
| Fagaceae | 3 | 8 | 2 | 8 | 4 | 4 | 0 | 1 |
| Frankeniaceae | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Garryaceae | 2 | 3 | 0 | 3 | 2 | 1 | 0 | 0 |
| Gentianaceae | 11 | 29 | 12 | 33 | 31 | 2 | 5 | 0 |
| Geraniaceae | 2 | 19 | 3 | 20 | 5 | 15 | 0 | 0 |
| Grossulariaceae | 1 | 26 | 16 | 35 | 32 | 3 | 5 | 2 |
| Haloragaceae | 1 | 10 | 0 | 10 | 7 | 3 | 0 | 0 |
| Heliotropiaceae | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |
| Hydrangeaceae | 2 | 2 | 0 | 2 | 2 | 0 | 0 | 0 |
| Hydrophyllaceae | 6 | 44 | 24 | 54 | 52 | 2 | 5 | 0 |
| Hypericaceae | 2 | 13 | 2 | 13 | 3 | 10 | 0 | 0 |
| Juglandaceae | 1 | 4 | 0 | 4 | 0 | 4 | 0 | 0 |
| Lamiaceae | 33 | 80 | 17 | 85 | 32 | 53 | 2 | 0 |
| Lauraceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Lentibulariaceae | 2 | 7 | 3 | 8 | 7 | 1 | 0 | 0 |
| Limnanthaceae | 2 | 4 | 0 | 4 | 2 | 2 | 1 | 0 |
| Linaceae | 3 | 9 | 3 | 10 | 5 | 5 | 0 | 2 |
| Linderniaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Linnaeaceae | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |
| Loasaceae | 1 | 6 | 2 | 7 | 7 | 0 | 1 | 1 |
| Lythraceae | 3 | 6 | 0 | 6 | 2 | 4 | 0 | 3 |
| Malvaceae | 13 | 32 | 5 | 34 | 16 | 18 | 5 | 2 |
| Mazaceae | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Menyanthaceae | 3 | 3 | 1 | 3 | 2 | 1 | 0 | 0 |
| Molluginaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Montiaceae | 7 | 32 | 9 | 36 | 35 | 1 | 9 | 1 |
| Moraceae | 2 | 2 | 0 | 2 | 0 | 2 | 0 | 0 |
| Myricaceae | 2 | 2 | 0 | 2 | 2 | 0 | 0 | 0 |
| Namaceae | 1 | 2 | 2 | 3 | 3 | 0 | 0 | 0 |
| Nitrariaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Nyctaginaceae | 2 | 8 | 4 | 10 | 7 | 3 | 3 | 4 |
| Nymphaeaceae | 2 | 6 | 1 | 6 | 4 | 2 | 0 | 0 |
| Oleaceae | 4 | 9 | 0 | 9 | 1 | 8 | 0 | 0 |
| Onagraceae | 15 | 79 | 14 | 83 | 69 | 14 | 1 | 6 |
| Orobanchaceae | 14 | 90 | 46 | 112 | 106 | 6 | 30 | 5 |
| Oxalidaceae | 1 | 9 | 0 | 9 | 3 | 6 | 0 | 0 |
| Paeoniaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Papaveraceae | 11 | 26 | 6 | 27 | 14 | 13 | 5 | 2 |
| Paulowniaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Penthoraceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Phrymaceae | 4 | 36 | 1 | 36 | 34 | 2 | 6 | 3 |
| Phytolaccaceae | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |
| Plantaginaceae | 20 | 143 | 55 | 170 | 127 | 43 | 49 | 5 |
| Plumbaginaceae | 2 | 3 | 2 | 4 | 2 | 2 | 0 | 0 |
| Polemoniaceae | 15 | 81 | 26 | 91 | 91 | 0 | 13 | 3 |
| Polygalaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Polygonaceae | 11 | 100 | 70 | 141 | 107 | 34 | 16 | 16 |
| Portulacaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Primulaceae | 9 | 40 | 6 | 42 | 33 | 9 | 8 | 0 |
| Ranunculaceae | 22 | 123 | 55 | 149 | 130 | 19 | 15 | 6 |
| Resedaceae | 1 | 4 | 0 | 4 | 0 | 4 | 0 | 0 |
| Rhamnaceae | 3 | 12 | 5 | 13 | 10 | 3 | 0 | 1 |
| Rosaceae | 48 | 230 | 51 | 248 | 142 | 106 | 18 | 16 |
| Rubiaceae | 5 | 21 | 1 | 21 | 11 | 10 | 0 | 2 |
| Salicaceae | 2 | 53 | 13 | 57 | 50 | 7 | 2 | 8 |
| Santalaceae | 5 | 13 | 6 | 17 | 16 | 1 | 2 | 4 |
| Sapindaceae | 2 | 11 | 2 | 12 | 5 | 7 | 0 | 0 |
| Sarcobataceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Sarraceniaceae | 2 | 4 | 1 | 4 | 0 | 4 | 0 | 0 |
| Saururaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Saxifragaceae | 24 | 78 | 14 | 84 | 83 | 1 | 11 | 1 |
| Scrophulariaceae | 4 | 9 | 0 | 9 | 4 | 5 | 0 | 0 |
| Simaroubaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Solanaceae | 11 | 37 | 5 | 38 | 3 | 35 | 0 | 1 |
| Tamaricaceae | 1 | 3 | 0 | 3 | 0 | 3 | 0 | 0 |
| Thymelaeaceae | 2 | 3 | 0 | 3 | 0 | 3 | 0 | 0 |
| Ulmaceae | 1 | 4 | 0 | 4 | 0 | 4 | 0 | 0 |
| Urticaceae | 2 | 4 | 3 | 6 | 3 | 3 | 0 | 0 |
| Valerianaceae | 4 | 16 | 3 | 16 | 11 | 5 | 1 | 0 |
| Verbenaceae | 1 | 5 | 0 | 5 | 3 | 2 | 0 | 0 |
| Violaceae | 1 | 28 | 9 | 32 | 26 | 6 | 1 | 6 |
| Vitaceae | 2 | 5 | 0 | 4 | 0 | 4 | 0 | 0 |
| Zygophyllaceae | 2 | 2 | 0 | 2 | 0 | 2 | 0 | 0 |
| Family | Genera | Species | Infraspecies | Terminal Taxa | Native | Exotic | Endemic | Excluded |
| Acoraceae | 1 | 2 | 0 | 2 | 1 | 1 | 0 | 0 |
| Alismataceae | 3 | 11 | 1 | 11 | 5 | 6 | 0 | 1 |
| Amaryllidaceae | 4 | 44 | 5 | 46 | 33 | 13 | 10 | 0 |
| Araceae | 8 | 16 | 0 | 15 | 11 | 4 | 0 | 2 |
| Asparagaceae | 12 | 29 | 15 | 36 | 23 | 13 | 2 | 1 |
| Asphodelaceae | 1 | 3 | 0 | 3 | 0 | 3 | 0 | 0 |
| Butomaceae | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0 |
| Commelinaceae | 2 | 2 | 0 | 2 | 0 | 2 | 0 | 0 |
| Cyperaceae | 15 | 266 | 32 | 274 | 240 | 34 | 1 | 4 |
| Hydrocharitaceae | 7 | 11 | 1 | 11 | 6 | 5 | 0 | 1 |
| Iridaceae | 5 | 22 | 10 | 27 | 19 | 8 | 5 | 0 |
| Juncaceae | 2 | 78 | 23 | 85 | 64 | 21 | 0 | 3 |
| Juncaginaceae | 1 | 5 | 2 | 6 | 6 | 0 | 0 | 0 |
| Liliaceae | 9 | 37 | 15 | 45 | 45 | 0 | 9 | 0 |
| Melanthiaceae | 5 | 11 | 9 | 15 | 15 | 0 | 3 | 0 |
| Orchidaceae | 13 | 42 | 15 | 49 | 48 | 1 | 1 | 0 |
| Poaceae | 117 | 408 | 121 | 451 | 259 | 192 | 16 | 23 |
| Pontederiaceae | 3 | 3 | 0 | 3 | 1 | 2 | 0 | 0 |
| Potamogetonaceae | 3 | 25 | 0 | 25 | 24 | 1 | 0 | 0 |
| Ruppiaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Scheuchzeriaceae | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Smilacaceae | 1 | 2 | 0 | 2 | 0 | 2 | 0 | 0 |
| Tofieldiaceae | 2 | 3 | 3 | 5 | 5 | 0 | 0 | 0 |
| Typhaceae | 2 | 10 | 0 | 10 | 7 | 3 | 0 | 1 |
| Zosteraceae | 3 | 5 | 0 | 5 | 4 | 1 | 0 | 0 |
