| Genus | Specific epithet | Family | Division | Common name | Abundance | var./ ssp. | Sub-specific tax. division |
|---|---|---|---|---|---|---|---|
| Ilex | decidua | Aquifoliaceae | Magnoliopsida | Possum-haw | C | ||
| Ilex | longipes | Aquifoliaceae | Magnoliopsida | Georgia Holly | - | var. | hirsuta |
| Ilex | opaca | Aquifoliaceae | Magnoliopsida | American Holly | I | ||
| Ilex | vomitoria | Aquifoliaceae | Magnoliopsida | Yaupon Holly | C | ||
| Ipomoea | cordatotriloba | Convolvulaceae | Magnoliopsida | Bindweed | F | ||
| Ipomoea | cordatotriloba | Convolvulaceae | Magnoliopsida | Bindweed | F | var. | cordatotriloba |
| Ipomoea | lacunosa | Convolvulaceae | Magnoliopsida | Pitted Morning-glory | F | ||
| Ipomoea | pandurata | Convolvulaceae | Magnoliopsida | Bigroot Morning-glory | I | ||
| Ipomopsis | rubra | Polemoniaceae | Magnoliopsida | Standing Cypress | R | ||
| Iresine | rhizomatosa | Amaranthaceae | Magnoliopsida | Rootstock Bloodleaf | I | ||
| Iris | hexagona | Iridaceae | Liliopsida | Dixie Iris | I | var. | flexicaulis |
| Iris | pallida | Iridaceae | Liliopsida | Bearded Iris | I | ||
| Isoetes | melanopoda | Isoetaceae | Pteridophyta | Quillwort | I | ||
| Isolepis | carinata | Cyperaceae | Liliopsida | Small Bulrush | F | ||
| Isolepis | molesta | Cyperaceae | Liliopsida | Small Bulrush | I | ||
| Iva | angustifolia | Asteraceae | Magnoliopsida | Narrowleaf Marshelder | C | ||
| Iva | annua | Asteraceae | Magnoliopsida | Marshelder | C | ||
| Jacquemontia | tamnifolia | Convolvulaceae | Magnoliopsida | Hairy Clustervine | - | ||
| Juglans | nigra | Juglandaceae | Magnoliopsida | Black Walnut | I | ||
| Juncus | acuminatus | Juncaceae | Liliopsida | Knotleaf Rush | F | ||
| Juncus | acuminatus | Juncaceae | Liliopsida | Knotleaf Rush | F | f. | sphaerocephalus |
| Juncus | brachycarpus | Juncaceae | Liliopsida | Whiteroot Rush | I | ||
| Juncus | bufonius | Juncaceae | Liliopsida | Toad Rush | - | ||
| Juncus | capitatus | Juncaceae | Liliopsida | Capped Rush | I | ||
| Juncus | debilis | Juncaceae | Liliopsida | Weak Rush | I | ||
| Juncus | dichotomous | Juncaceae | Liliopsida | Forked Rush | F | ||
| Juncus | diffusissimus | Juncaceae | Liliopsida | Slimpod Rush | I | ||
| Juncus | dudleyi | Juncaceae | Liliopsida | Dudley Rush | I | ||
| Juncus | effusus | Juncaceae | Liliopsida | Common Rush | C | var. | solutus |
| Juncus | interior | Juncaceae | Liliopsida | Inland Rush | I | ||
| Juncus | marginatus | Juncaceae | Liliopsida | Grassleaf Rush | F | ||
| Juncus | repens | Juncaceae | Liliopsida | Creeping Rush | R | ||
| Juncus | scirpoides | Juncaceae | Liliopsida | Needlepod Rush | I | ||
| Juncus | tenuis | Juncaceae | Liliopsida | Slender Rush | I | ||
| Juncus | validus | Juncaceae | Liliopsida | Roundhead Rush | C | ||
| Juncus | validus | Juncaceae | Liliopsida | Roundhead Rush | C | var. | validus |
| Juniperus | virginiana | Cupressaceae | Pinophyta | Eastern Red Cedar | F | ||
| Justicia | americana | Acanthaceae | Magnoliopsida | American Water-willow | I | ||
| Justicia | ovata | Acanthaceae | Magnoliopsida | Lanceleaved Water-willow | F | var. | lanceolata |
| Krameria | lanceolata | Krameriaceae | Magnoliopsida | Rattany-vine | I | ||
| Krigia | cespitosa | Asteraceae | Magnoliopsida | Weedy Dwarf Dandelion | F | ||
| Krigia | dandelion | Asteraceae | Magnoliopsida | Tuber Dwarf Dandelion | I | ||
| Krigia | gracilis | Asteraceae | Magnoliopsida | Dwarf Dandelion | C | ||
| Krigia | occidentalis | Asteraceae | Magnoliopsida | Western Dwarf Dandelion | I | ||
| Krigia | virginica | Asteraceae | Magnoliopsida | Virginia Dwarf Dandelion | I | ||
| Kyllinga | odorata | Cyperaceae | Liliopsida | Fragrant Flatsedge | I | ||
| Lactuca | canadensis | Asteraceae | Magnoliopsida | Wild Lettuce | F | ||
| Lactuca | floridana | Asteraceae | Magnoliopsida | Florida Lettuce | I | ||
| Lactuca | hirsuta | Asteraceae | Magnoliopsida | Hairy Lettuce | I | var. | albiflora |
| Lactuca | ludoviciana | Asteraceae | Magnoliopsida | Wild Lettuce | I | ||
| Lactuca | serriola | Asteraceae | Magnoliopsida | Prickly Lettuce | I | ||
| Lagerstroemia | indica | Lythraceae | Magnoliopsida | Crepe Myrtle | I | ||
| Lamium | amplexicaule | Lamiaceae | Magnoliopsida | Henbit | F | ||
| Lantana | camara | Verbenaceae | Magnoliopsida | West-Indian Lantana | I | ||
| Lantana | urticoides | Verbenaceae | Magnoliopsida | Lantana | I | ||
| Lathryus | hirsutus | Fabaceae | Magnoliopsida | Singletary Pea | F | ||
| Lathyrus | pusillus | Fabaceae | Magnoliopsida | Low Pea | I | ||
| Lechea | mucronata | Cistaceae | Magnoliopsida | Hairy Pinweed | F | ||
| Lechea | san-sabeana | Cistaceae | Magnoliopsida | San Saba Pinweed | I | ||
| Lechea | tenuifolia | Cistaceae | Magnoliopsida | Narrowleaf Pinweed | F | ||
| Leersia | lenticularis | Poaceae | Liliopsida | Catchfly Grass | I | ||
| Leersia | virginica | Poaceae | Liliopsida | Whitegrass | I | ||
| Lemna | minima | Lemnaceae | Liliopsida | Duckweed | I | ||
| Lepidium | densiflorum | Brassicaceae | Magnoliopsida | Prairie Pepperweed | I | ||
| Lepidium | virginicum | Brassicaceae | Magnoliopsida | Virginia Pepperweed | F | var. | medium |
| Lepidium | virginicum | Brassicaceae | Magnoliopsida | Virginia Pepperweed | F | var. | virginicum |
| Lepuropetalon | spathulatum | Saxifragacae | Magnoliopsida | Petite-plant | I | ||
| Lespedeza | cuneata | Fabaceae | Magnoliopsida | Sericea Bushclover | I | ||
| Lespedeza | hirta | Fabaceae | Magnoliopsida | Hairy Bushclover | I | ||
| Lespedeza | repens | Fabaceae | Magnoliopsida | Creeping Bushclover | I | ||
| Lespedeza | striata | Fabaceae | Magnoliopsida | Japanese Bushclover | I | ||
| Lespedeza | stuevei | Fabaceae | Magnoliopsida | Stueve Bushclover | F | ||
| Lespedeza | virginica | Fabaceae | Magnoliopsida | Slender Bushclover | I | ||
| Leucospora | multifida | Scrophulariaceae | Magnoliopsida | Narrowleaf Conobea | I | ||
| Liatris | cymosa | Asteraceae | Magnoliopsida | Branched Gayfeather | R | ||
| Liatris | elegans | Asteraceae | Magnoliopsida | Pinkscale Gayfeather | R | ||
| Liatris | mucronata | Asteraceae | Magnoliopsida | Gayfeather | I | ||
| Liatris | squarrosa | Asteraceae | Magnoliopsida | Gayfeather | F | ||
| Liatris | squarrosa | Asteraceae | Magnoliopsida | Gayfeather | F | var. | alabamensis |
| Ligustrum | lucidum | Oleaceae | Magnoliopsida | Wax-leaf Ligustrum | R | ||
| Ligustrum | sinense | Oleaceae | Magnoliopsida | Chinese Privet | C | ||
| Limnosciadum | pinnatum | Apiaceae | Magnoliopsida | Arkansas Dogshade | I | ||
| Limnosciadum | pumilum | Apiaceae | Magnoliopsida | Prairie Dogshade | I | ||
| Linaria | canadensis | Scrophulariaceae | Magnoliopsida | Oldfield Toadflax | C | var. | canadensis |
| Linaria | canadensis | Scrophulariaceae | Magnoliopsida | Texas Toadflax | C | var. | texana |
| Lindernia | dubia | Scrophulariaceae | Magnoliopsida | Clasping False Pimpernel | I | var. | anagallidea |
| Linum | medium | Linaceae | Magnoliopsida | Texas Flax | C | var. | texanum |
| Liquidambar | styraciflua | Hamamelidaceae | Magnoliopsida | Sweet Gum | I | ||
| Liriope | spicata | Liliaceae | Liliopsida | Creeping Lilyturf | R | ||
| Lithospermum | incisum | Boraginaceae | Magnoliopsida | Narrowleaf Puccoon | I | ||
| Lobelia | appendiculata | Campanulaceae | Magnoliopsida | Earflower Lobelia | F | ||
| Lobelia | cardinalis | Campanulaceae | Magnoliopsida | Cardinal Flower | R | ||
| Lobelia | puberula | Campanulaceae | Magnoliopsida | Downy Lobelia | I | var. | pauciflora |
| Lobelia | puberula | Campanulaceae | Magnoliopsida | Downy Lobelia | I | var. | puberula |
| Loeflingia | squarrosa | Caryophyllaceae | Magnoliopsida | Spreading Loeflingia | R | ||
| Lolium | perenne | Poaceae | Liliopsida | Perennial Ryegrass | C | ||
| Lonicera | japonica | Caprifoliaceae | Magnoliopsida | Japanese Honeysuckle | C | ||
| Lonicera | sempervirens | Caprifoliaceae | Magnoliopsida | Scarlet Honeysuckle | I | ||
| Lotus | unifoliatus | Fabaceae | Magnoliopsida | Pursh Deervetch | R | var. | unifoliatus |
| Ludwigia | alternifolia | Onagraceae | Magnoliopsida | Bushy Seedbox | I | ||
| Ludwigia | decurrens | Onagraceae | Magnoliopsida | Primrose-willow | I | ||
| Ludwigia | glandulosa | Onagraceae | Magnoliopsida | Torrey Seedbox | I | ssp. | brachycarpa |
| Ludwigia | glandulosa | Onagraceae | Magnoliopsida | Torrey Seedbox | I | ssp. | glandulosa |
| Ludwigia | palustris | Onagraceae | Magnoliopsida | American Seedbox | C | ||
| Ludwigia | peploides | Onagraceae | Magnoliopsida | Smooth Water-primrose | C | ||
| Lupinus | subcarnosus | Fabaceae | Magnoliopsida | Texas Bluebonnet | C | ||
| Lupinus | texensis | Fabaceae | Magnoliopsida | Texas Bluebonnet | F | ||
| Luzula | bulbosa | Juncaceae | Liliopsida | Bulb Woodrush | I | ||
| Lycopus | rubellus | Lamiaceae | Magnoliopsida | Arkansas Bugleweed | I | ||
| Lygodium | japonicum | Schizaeaceae | Pteridophyta | Japanese Climbing Fern | R | ||
| Lythrum | alatum | Lythraceae | Magnoliopsida | Lanceleaf Loosestrife | I | var. | lanceolatum |
| Maclura | pomifera | Moraceae | Magnoliopsida | Bois D'Arc | I | ||
| Malvaviscus | arboreus | Malvaceae | Magnoliopsida | Drummond Turk's-cap | F | var. | drummondii |
| Manfreda | variegata | Agavaceae | Liliopsida | Rattlesnake Master | R | ||
| Marsilea | macropoda | Marsileaceae | Pteridophyta | Water-clover | R | ||
| Matelea | cyanchoides | Asclepiadaceae | Magnoliopsida | Sand Milkvine | I | ||
| Matelea | gonocarpos | Asclepiadaceae | Magnoliopsida | Milkvine | F | ||
| Mecardonia | acuminata | Scrophulariaceae | Magnoliopsida | Sawtooth Water-hyssop | I | ||
| Mecardonia | procumbens | Scrophulariaceae | Magnoliopsida | Prostrate Water-hyssop | I | ||
| Medicago | arabica | Fabaceae | Magnoliopsida | Spotted Medic | I | ||
| Medicago | lupulina | Fabaceae | Magnoliopsida | Black Medic | I | ||
| Medicago | orbicularis | Fabaceae | Magnoliopsida | Button Clover | F | ||
| Medicago | polymorpha | Fabaceae | Magnoliopsida | Medic | F | ||
| Medicago | sativa | Fabaceae | Magnoliopsida | Alfalfa | I | ||
| Melia | azedarach | Meliaceae | Magnoliopsida | Chinaberry | F | ||
| Melica | mutica | Poaceae | Liliopsida | Twoflower Melic | F | ||
| Melilotus | indicus | Fabaceae | Magnoliopsida | Yellow Sweetclover | C | ||
| Melilotus | officinalis | Fabaceae | Magnoliopsida | Yellow Sweetclover | - | ||
| Melothria | pendula | Cucurbitaceae | Magnoliopsida | Melonette | F | ||
| Mikania | scandens | Asteraceae | Magnoliopsida | Climbing Hemp | I | ||
| Mimosa | nuttallii | Mimosaceae | Magnoliopsida | Catclaw Sensitive-briar | F | ||
| Mimosa | strigillosa | Mimosaceae | Magnoliopsida | Herbaceous Mimosa | I | ||
| Mirabilis | albida | Nyctaginaceae | Magnoliopsida | White Four-O'Clock | F | ||
| Mirabilis | jalapa | Nyctaginaceae | Magnoliopsida | Four-O'Clock | R | ||
| Mirabilis | linearis | Nyctaginaceae | Magnoliopsida | Linearleaf Four-O'Clock | I | ||
| Mirabilis | nyctaginea | Nyctaginaceae | Magnoliopsida | Wild Four-O'Clock | I | ||
| Mitchella | repens | Rubiaceae | Magnoliopsida | Partridge-berry | I | ||
| Modiola | caroliniana | Malvaceae | Magnoliopsida | Carolina Modiola | C | ||
| Mollugo | verticillata | Molluginaceae | Magnoliopsida | Green Carpetweed | F | ||
| Monarda | citriodora | Lamiaceae | Magnoliopsida | Lemon Beebalm | F | ssp. | citriodora |
| Monarda | clinopodioides | Lamiaceae | Magnoliopsida | Basil Beebalm | I | ||
| Monarda | fistulosa | Lamiaceae | Magnoliopsida | Wild Bergamot | F | ||
| Monarda | lindheimeri | Lamiaceae | Magnoliopsida | Lindheimer Bergamot | I | ||
| Monarda | punctata | Lamiaceae | Magnoliopsida | Spotted Beebalm | F | var. | intermedia |
| Monarda | punctata | Lamiaceae | Magnoliopsida | Spotted Beebalm | F | var. | lasiodonta |
| Morus | rubra | Moraceae | Magnoliopsida | Red Mulberry | F | ||
| Muhlenbergia | capillaris | Poaceae | Liliopsida | Hairyawn Muhly | I | ||
| Muhlenbergia | schreiberi | Poaceae | Liliopsida | Nimblewill | - | ||
| Myosotis | macrosperma | Boraginaceae | Magnoliopsida | Spring Forget-me-not | F | var. | macrosperma |
| Myosotis | verna | Boraginaceae | Magnoliopsida | Early Scorpion-grass | I | ||
| Myosurus | minimus | Ranunculaceae | Magnoliopsida | Tiny Mousetail | I | ||
| Myrica | cerifera | Myricaceae | Magnoliopsida | Southern Wax-myrtle | I | ||
| Myriophyllum | heterophyllum | Haloragaceae | Magnoliopsida | Changeleaf Parrot's Feather | F | ||
| Myriophyllum | pinnatum | Haloragaceae | Magnoliopsida | Green Parrot's Feather | I | ||
| Najas | guadalupensis | Najadaceae | Liliopsida | Southern Naiad | R | ||
| Nandina | domestica | Berberidaceae | Magnoliopsida | Heavenly Bamboo | R | ||
| Narcissus | jonquilla | Liliaceae | Liliopsida | Jonquil | I | ||
| Nasella | leucotricha | Poaceae | Liliopsida | Texas Wintergrass | F | ||
| Nelumbo | lutea | Nelumbonaceae | Magnoliopsida | Yellow Lotus | R | ||
| Nemophila | aphylla | Hydrophyllaceae | Magnoliopsida | Smallflower Nemophila | I | ||
| Neobeckia | aquatica | Brassicaceae | Magnoliopsida | Water Horseradish | R | ||
| Neptunia | lutea | Mimosaceae | Magnoliopsida | Yellow Neptunia | I | ||
| Neptunia | pubescens | Mimosaceae | Magnoliopsida | Prairie Neptunia | I | var. | pubescens |
| Nothoscordum | bivalve | Liliaceae | Liliopsida | Crow-poison | C | ||
| Nuphar | lutea | Nymphaeaceae | Magnoliopsida | Spatterdock | I | ssp. | advena |
| Nymphaea | odorata | Nymphaeaceae | Magnoliopsida | American Waterlily | R | ssp. | odorata |
| Nyssa | sylvatica | Nyssaceae | Magnoliopsida | Black Tupelo | I | var. | sylvatica |
| Oenothera | heterophylla | Onagraceae | Magnoliopsida | Varileaf Evening Primrose | I | ssp. | heterophylla |
| Oenothera | laciniata | Onagraceae | Magnoliopsida | Cutleaf Evening Primrose | C | ||
| Oenothera | linifolia | Onagraceae | Magnoliopsida | Threadleaf Sundrops | I | ||
| Oenothera | spachiana | Onagraceae | Magnoliopsida | Spach Evening Primrose | I | ||
| Oenothera | speciosa | Onagraceae | Magnoliopsida | Showy Evening Primrose | F | ||
| Oldenlandia | boscii | Rubiaceae | Magnoliopsida | - | I | ||
| Oldenlandia | uniflora | Rubiaceae | Magnoliopsida | - | R | ||
| Oligoneuron | nitidum | Asteraceae | Magnoliopsida | Flat-top Goldenrod | I | ||
| Onoclea | sensibilis | Dryopteridaceae | Pteridophyta | Sensitive Fern | I | ||
| Onosmodium | molle | Boraginaceae | Magnoliopsida | Western Marbleseed | R | ssp. | occidentale |
| Ophioglossum | crotalophoroides | Ophioglossaceae | Pteridophyta | Heartleaf Adder's Tongue | - | ||
| Oplismenus | hirtellus | Poaceae | Liliopsida | Basketgrass | I | ||
| Opuntia | humifusa | Cactaceae | Magnoliopsida | Eastern Prickly-pear | I | var. | humifusa |
| Opuntia | lindheimeri | Cactaceae | Magnoliopsida | Cowtongue Prickly-pear | R | var. | linguiformis |
| Opuntia | macrorhiza | Cactaceae | Magnoliopsida | Plains Prickly-pear | I | var. | macrorhiza |
| Orbexilum | pedunculatum | Fabaceae | Magnoliopsida | Sampson's Snakeroot | R | var. | pedunculatum |
| Orbexilum | simplex | Fabaceae | Magnoliopsida | Singlestem Snakeroot | I | ||
| Orobanche | multiflora | Orobanchaceae | Magnoliopsida | Largeflower Broomrape | I | ||
| Osmunda | cinnamomea | Osmundaceae | Pteridophyta | Cinnamon Fern | R | ||
| Oxalis | corniculata | Oxalidaceae | Magnoliopsida | Creeping Woodsorrel | I | ||
| Oxalis | dillenii | Oxalidaceae | Magnoliopsida | Dillen Woodsorrel | F | ||
| Oxalis | rubra | Oxalidaceae | Magnoliopsida | Pink Shamrock | R | ||
| Oxalis | stricta | Oxalidaceae | Magnoliopsida | Yellow Woodsorrel | C | ||
| Oxalis | violacea | Oxalidaceae | Magnoliopsida | Violet Woodsorrel | I | ||
| Packera | obovata | Asteraceae | Magnoliopsida | Golden Groundsel | R | ||
| Packera | tampicana | Asteraceae | Magnoliopsida | Butterweed | F | ||
| Palafoxia | rosea | Asteraceae | Magnoliopsida | Rose Palafoxia | F | ||
| Palafoxia | rosea | Asteraceae | Magnoliopsida | Rose Palafoxia | F | var. | rosea |
| Palafoxia | texana | Asteraceae | Magnoliopsida | Texas Palafoxia | I | var. | ambigua |
| Palafoxia | texana | Asteraceae | Magnoliopsida | Texas Palafoxia | I | var. | texana |
| Panicum | anceps | Poaceae | Liliopsida | Beaked Panicum | I | ||
| Panicum | brachyanthum | Poaceae | Liliopsida | Pimple Panicum | I | ||
| Panicum | dichotomiflorum | Poaceae | Liliopsida | Fall Panicum | F | ||
| Panicum | diffusum | Poaceae | Liliopsida | Spreading Panicum | - | ||
| Panicum | gymnocarpon | Poaceae | Liliopsida | Savannah Panicum | I | ||
| Panicum | hallii | Poaceae | Liliopsida | Halls Panicum | - | var. | hallii |
| Panicum | hians | Poaceae | Liliopsida | Gaping Panicum | C | ||
| Panicum | rigidulum | Poaceae | Liliopsida | Redtop Panicum | C | ||
| Panicum | virgatum | Poaceae | Liliopsida | Switchgrass | I | ||
| Parietaria | obtusa | Urticaceae | Magnoliopsida | Pellitory | I | ||
| Parietaria | pensylvanica | Urticaceae | Magnoliopsida | Pennsylvania Pellitory | F | ||
| Parkinsonia | aculeata | Caesalpiniaceae | Magnoliopsida | Retama | R | ||
| Paronychia | lindheimeri | Caryophyllaceae | Magnoliopsida | Lindheimer Nailwort | R | ||
| Parthenocissus | quinquefolia | Vitaceae | Magnoliopsida | Virginia Creeper | I | ||
| Paspalidium | geminatum | Poaceae | Liliopsida | Paspalidium | I | var. | geminatum |
| Paspalum | dilatatum | Poaceae | Liliopsida | Dallisgrass | F | ||
| Paspalum | floridanum | Poaceae | Liliopsida | Florida Paspalum | F | var. | glabratum |
| Paspalum | fluitans | Poaceae | Liliopsida | Water Paspalum | I | ||
| Paspalum | laeve | Poaceae | Liliopsida | Field Paspalum | - | ||
| Paspalum | notatum | Poaceae | Liliopsida | Bahiagrass | F | var. | notatum |
| Paspalum | notatum | Poaceae | Liliopsida | Bahiagrass | F | var. | saurae |
| Paspalum | plicatulum | Poaceae | Liliopsida | Brownseed Paspalum | C | ||
| Paspalum | pubiflorum | Poaceae | Liliopsida | Hairyseed Paspalum | - | ||
| Paspalum | setaceum | Poaceae | Liliopsida | Thin Paspalum | I | var. | setaceum |
| Paspalum | setaceum | Poaceae | Liliopsida | Thin Paspalum | I | var. | stramineum |
| Paspalum | urvillei | Poaceae | Liliopsida | Vaseygrass | I | ||
| Passiflora | incarnata | Passifloraceae | Magnoliopsida | Maypop | F | ||
| Passiflora | lutea | Passifloraceae | Magnoliopsida | Yellow Passionflower | F | ||
| Pediomelum | hypogaeum | Fabaceae | Magnoliopsida | Edible Scurfpea | I | var. | subulatum |
| Pediomelum | rhombifolium | Fabaceae | Magnoliopsida | Roundleaf Scurfpea | I | ||
| Penstemon | australis | Scrophulariaceae | Magnoliopsida | Southern Beardtongue | I | ssp. | laxiflorus |
| Penthorum | sedoides | Saxifragaceae | Magnoliopsida | Ditch-Stonecrop | I | ||
| Perilla | frutescens | Lamiaceae | Magnoliopsida | Beefsteak Plant | I | ||
| Petrorhagia | dubia | Caryophyllaceae | Magnoliopsida | Childling Pink | I | ||
| Phacelia | glabra | Hydrophyllaceae | Magnoliopsida | Smooth Phacelia | I | ||
| Phacelia | hirsuta | Hydrophyllaceae | Magnoliopsida | Hairy Phacelia | I | ||
| Phacelia | patuliflora | Hydrophyllaceae | Magnoliopsida | Sand Phacelia | I | ||
| Phalaris | caroliniana | Poaceae | Liliopsida | Carolina Canarygrass | F | ||
| Phlox | cuspidata | Polemoniaceae | Magnoliopsida | Pointed Phlox | C | ||
| Phlox | cuspidata | Polemoniaceae | Magnoliopsida | Pointed Phlox | C | var. | cuspidata |
| Phlox | drummondii | Polemoniaceae | Magnoliopsida | Drummond Phlox | I | var. | peregrina |
| Phlox | pilosa | Polemoniaceae | Magnoliopsida | Downy Phlox | R | ||
| Phoradendron | tomentosum | Viscaceae | Magnoliopsida | Mistletoe | C | ||
| Phyla | lanceolata | Verbenaceae | Magnoliopsida | Lanceleaf Frogfruit | C | ||
| Phyla | nodiflora | Verbenaceae | Magnoliopsida | Common Frogfruit | F | ||
| Phyla | nodiflora | Verbenaceae | Magnoliopsida | Common Frogfruit | F | var. | nodiflora |
| Phyllanthus | abnormis | Euphorbiaceae | Magnoliopsida | Drummond Leaf-flower | I | var. | abnormis |
| Phyllanthus | caroliniensis | Euphorbiaceae | Magnoliopsida | Carolina Leaf-flower | I | ssp. | carolinIensis |
| Phyllanthus | pudens | Euphorbiaceae | Magnoliopsida | Birdseed Leaf-flower | I | ||
| Physalis | cinerascens | Solanaceae | Magnoliopsida | Beach Groundcherry | F | var. | cinerascens |
| Physalis | heterophylla | Solanaceae | Magnoliopsida | Clammy Groundcherry | I | var. | heterophylla |
| Physalis | pubescens | Solanaceae | Magnoliopsida | Downy Groundcherry | C | ||
| Physalis | pubescens | Solanaceae | Magnoliopsida | Downy Groundcherry | C | var. | integrifolia |
| Physostegia | angustifolia | Lamiaceae | Magnoliopsida | Obedient-plant | I | ||
| Physostegia | intermedia | Lamiaceae | Magnoliopsida | Intermediate Obedient-plant | F | ||
| Physostegia | pulchella | Lamiaceae | Magnoliopsida | Obedient-plant | C | ||
| Phytolacca | americana | Phytolaccaceae | Magnoliopsida | Pokeweed | I | ||
| Pinus | echinata | Pinaceae | Pinophyta | Shortleaf Pine | R | ||
| Pinus | taeda | Pinaceae | Pinophyta | Loblolly Pine | I | ||
| Piptochaetium | avenaceum | Poaceae | Liliopsida | Blackseed Needlegrass | F | ||
| Planera | aquatica | Ulmaceae | Magnoliopsida | Water Elm | F | ||
| Plantago | aristata | Plantaginaceae | Magnoliopsida | Bottlebrush Plantain | C | ||
| Plantago | heterophylla | Plantaginaceae | Magnoliopsida | Simplespike Plantain | I | ||
| Plantago | hookeriana | Plantaginaceae | Magnoliopsida | Hooker Plantain | I | ||
| Plantago | patagonica | Plantaginaceae | Magnoliopsida | Bristlebract Plantain | I | ||
| Plantago | rhodosperma | Plantaginaceae | Magnoliopsida | Redseed Plantain | F | ||
| Plantago | virginica | Plantaginaceae | Magnoliopsida | Paleseed Plantain | C | ||
| Plantago | wrightiana | Plantaginaceae | Magnoliopsida | Wright Plantain | F | ||
| Platanus | occidentalis | Platanaceae | Magnoliopsida | American Sycamore | I | ||
| Platycladus | orientalis | Cupressaceae | Pinophyta | Arborvitae | R | ||
| Pleopeltis | polypodioides | Polypodiaceae | Pteridophyta | Resurrection Fern | F | ssp. | michauxiana |
| Pluchea | camphorata | Asteraceae | Magnoliopsida | Camphor Marsh-fleabane | F | ||
| Pluchea | foetida | Asteraceae | Magnoliopsida | Stinking Marsh-fleabane | R | ||
| Pluchea | odorata | Asteraceae | Magnoliopsida | Purple Marsh-fleabane | I | ||
| Poa | annua | Poaceae | Liliopsida | Annual Bluegrass | I | ||
| Poa | autumnalis | Poaceae | Liliopsida | Autumn Bluegrass | I | ||
| Poa | chapmaniana | Poaceae | Liliopsida | Chapman Bluegrass | I | ||
| Polanisia | erosa | Capparaceae | Magnoliopsida | Large Clammyweed | R | ssp. | erosa |
| Polygala | incarnata | Polygalaceae | Magnoliopsida | Pink Milkwort | R | ||
| Polygala | polygama | Polygalaceae | Magnoliopsida | Bitter Milkwort | I | ||
| Polygala | verticillata | Polygalaceae | Magnoliopsida | Whorled Milkwort | I | ||
| Polygonum | hydropiperoides | Polygonaceae | Magnoliopsida | Swamp Smartweed | C | ||
| Polygonum | lapathifolium | Polygonaceae | Magnoliopsida | Curltop Smartweed | I | ||
| Polygonum | pensylvanicum | Polygonaceae | Magnoliopsida | Pennsylvania Smartweed | F | ||
| Polygonum | persicaria | Polygonaceae | Magnoliopsida | Lady's Thumb | I | ||
| Polygonum | punctatum | Polygonaceae | Magnoliopsida | Water Smartweed | C | ||
| Polygonum | ramosissimum | Polygonaceae | Magnoliopsida | Bushy Knotweed | I | ||
| Polygonum | setaceum | Polygonaceae | Magnoliopsida | Smartweed | I | ||
| Polypogon | monspeliensis | Poaceae | Liliopsida | Rabbitfoot Polypogon | R | ||
| Polypremum | procumbens | Buddlejaceae | Magnoliopsida | Juniperleaf | F | ||
| Polytaenia | nuttallii | Apiaceae | Magnoliopsida | Prairie Parsley | F | ||
| Polytaenia | texana | Apiaceae | Magnoliopsida | Texas Prairie Parsley | I | ||
| Poncirus | trifoliolata | Rutaceae | Magnoliopsida | Bitter Orange | R | ||
| Pontederia | cordata | Pontederiaceae | Liliopsida | Pickerelweed | R | var. | lanceolata |
| Populus | deltoides | Salicaceae | Magnoliopsida | Eastern Cottonwood | I | ||
| Portulaca | oleracea | Portulacaceae | Magnoliopsida | Common Purslane | I | ||
| Portulaca | pilosa | Portulacaceae | Magnoliopsida | Chisme | I | ||
| Portulaca | umbraticola | Portulacaceae | Magnoliopsida | Wingpod Portulaca | I | ||
| Potamogeton | diversifolius | Potamogetonaceae | Liliopsida | Waterthread Pondweed | I | ||
| Potamogeton | diversifolius | Potamogetonaceae | Liliopsida | Waterthread Pondweed | I | var. | diversifolius |
| Prosopis | glandulosa | Mimosaceae | Magnoliopsida | Honey Mesquite | C | var. | glandulosa |
| Prunella | vulgaris | Lamiaceae | Magnoliopsida | Self-heal | F | ||
| Prunella | vulgaris | Lamiaceae | Magnoliopsida | Self-heal | F | var. | hispida |
| Prunus | angustifolia | Rosaceae | Magnoliopsida | Chickasaw Plum | I | ||
| Prunus | caroliniana | Rosaceae | Magnoliopsida | Cherry-laurel | I | ||
| Prunus | gracilis | Rosaceae | Magnoliopsida | Oklahoma Plum | F | ||
| Prunus | mexicana | Rosaceae | Magnoliopsida | Mexican Plum | F | ||
| Prunus | persica | Rosaceae | Magnoliopsida | Peach | R | ||
| Prunus | serotina | Rosaceae | Magnoliopsida | Black Cherry | I | var. | serotina |
| Psoralidium | tenuiflorum | Fabaceae | Magnoliopsida | Slimleaf Scurfpea | - | ||
| Pterocaulon | virgatum | Asteraceae | Magnoliopsida | Wand Blackroot | I | ||
| Ptilimnium | nuttallii | Apiaceae | Magnoliopsida | Nuttall Mock Bishops Weed | C | ||
| Pueraria | lobata | Fabaceae | Magnoliopsida | Kudzu | R | ||
| Pyracantha | coccinea | Rosaceae | Magnoliopsida | Scarlet Firethorn | I | ||
| Pyrrhopappus | carolinianus | Asteraceae | Magnoliopsida | Carolina False Dandelion | F | ||
| Pyrrhopappus | multicaulis | Asteraceae | Magnoliopsida | Manystem False Dandelion | I | ||
| Pyrus | calleryana | Rosaceae | Magnoliopsida | Callery Pear | I | ||
| Pyrus | communis | Rosaceae | Magnoliopsida | Common Pear | I |