Note: Some species are placed in multiple categories when colors and/or shapes are subjective or ambiguous.
Pink or Red
Three petals
Asarum canadense
Murdannia keisak
Trillium cuneatum
Trillium grandiflorum
Trillium sessile
Four petals
Callicarpa americana
Galium pilosum
Oenothera speciosa
Rhexia mariana
Rhexia virginica
Five petals
Agalinis purpurea
Aquilegia canadensis
Asclepias incarnata
Asclepias purpurascens
Asclepias syriaca
Campsis radicans
Claytonia virginica
Dianthus armeria
Elephantopus carolinianus
Epigaea repens
Erodium cicutarium
Geranium carolinianum
Geranium dissectum
Geranium maculatum
Geranium molle
Geranium pusillum
Gypsophila muralis
Malva neglecta
Oxalis violacea
Persicaria hydropiperoides
Persicaria sagittata
Phlox divaricata
Phlox paniculata
Phlox subulata
Primula meadia
Rosa carolina
Rosa palustris
Rubus bifrons
Rubus phoenicolasius
Sabatia angularis
Saponaria officinalis
Silene caroliniana
Six petals
Allium canadense
Allium cernuum
Allium vineale
Brasenia schreberi
Cuphea viscosissima
Lythrum salicaria
Many petals
Carduus acanthoides
Carduus nutans
Centaurea stoebe
Centaurea x moncktonii
Cirsium arvense
Cirsium discolor
Cirsium vulgare
Elephantopus carolinianus
Pea-shaped petals
Kummerowia stipulacea
Kummerowia striata
Lathyrus latifolius
Lespedeza frutescens
Lespedeza procumbens
Lespedeza repens
Lespedeza virginica
Securigera varia
Strophostyles helvola
Strophostyles umbellata
Vicia sativa
Vicia villosa
Irregular
Allium vineale
Arctium minus
Campsis radicans
Carduus nutans
Cirsium arvense
Cirsium vulgare
Clinopodium vulgare
Cypripedium acaule
Epifagus virginiana
Epipactis helleborine
Eutrochium dubium
Eutrochium fistulosum
Eutrochium maculatum
Eutrochium purpureum
Lamium amplexicaule
Lamium purpureum
Leonurus cardiaca
Liatris squarrosa
Lobelia cardinalis
Lonicera sempervirens
Mazus pumilus
Monarda didyma
Monarda fistulosa
Perilla frutescens
Persicaria longiseta
Persicaria pensylvanica
Phryma leptostachya
Physostegia virginiana
Polygala sanguinea
Polygala verticillata
Rumex obtusifolius
Securigera varia
Teucrium canadense
Trifolium arvense
Trifolium pratense
Blue or Purple
Three petals
Commelina communis
Tradescantia virginiana
Four petals
Cardamine douglassii
Clematis ochroleuca
Cunila origanoides
Diodella teres
Hesperis matronalis
Houstonia caerulea
Houstonia longifolia
Houstonia purpurea
Houstonia pusilla
Justicia americana
Mentha arvensis
Pycnanthemum tenuifolium
Sherardia arvensis
Veronica arvensis
Veronica hederifolia
Veronica officinalis
Veronica persica
Veronica polita
Veronica serpyllifolia
Five petals
Asclepias purpurascens
Cymbalaria muralis
Cynoglossum virginianum
Delphinium tricorne
Echium vulgare
Ipomoea hederacea
Liatris pilosa
Lobelia puberula
Lobelia siphilitica
Mertensia virginica
Mimulus alatus
Mimulus ringens
Myosotis ramosissima
Myosotis stricta
Orobanche uniflora
Penstemon canescens
Penstemon hirsutus
Penstemon laevigatus
Phacelia covillei
Phacelia dubia
Phlox divaricata
Polemonium reptans
Rubus odoratus
Ruellia caroliniensis
Solanum dulcamara
Triodanis perfoliata
Valerianella locusta
Verbena hastata
Verbena simplex
Vinca major
Vinca minor
Viola affinis
Viola bicolor
Viola cucullata
Viola hirsutula
Viola palmata
Viola pedata
Viola sagittata
Viola sororia
Viola subsinuata
Six petals
Anemone americana
Iris versicolor
Lythrum salicaria
Pontederia cordata
Sisyrinchium angustifolium
Sisyrinchium mucronatum
Many petals
Anemone americana
Centaurea cyanus
Centaurea x moncktonii
Cichorium intybus
Conoclinium coelestinum
Echinacea purpurea
Lactuca floridana
Symphyotrichum laeve
Symphyotrichum novae-angliae
Symphyotrichum patens
Symphyotrichum puniceum
Pea-shaped petals
Amphicarpaea bracteata
Desmodium nudiflorum
Lespedeza frutescens
Lespedeza procumbens
Lespedeza repens
Vicia villosa
Irregular
Ajuga reptans
Corydalis incisa
Cymbalaria muralis
Dipsacus fullonum
Galearis spectabilis
Glechoma hederacea
Hedeoma pulegioides
Justicia americana
Lindernia dubia
Lobelia inflata
Monarda fistulosa
Prunella vulgaris
Pycnanthemum incanum
Pycnanthemum muticum
Salvia lyrata
Scutellaria elliptica
Scutellaria incana
Scutellaria integrifolia
Scutellaria nervosa
Symplocarpus foetidus
Trichostema dichotomum
White
Three petals
Galium tinctorium
Sagittaria latifolia
Trillium grandiflorum
Four petals
Abdra brachycarpa
Alliaria petiolata
Arabidopsis lyrata
Arabidopsis thaliana
Arabis patens
Boechera laevigata
Capsella bursa-pastoris
Cardamine bulbosa
Cardamine concatenata
Cardamine douglassii
Cardamine hirsuta
Cardamine pensylvanica
Clematis terniflora
Clematis virginiana
Dicentra canadensis
Dicentra cucullaria
Diodia virginiana
Draba verna
Euphorbia maculata
Galium aparine
Galium asprellum
Galium concinnum
Galium obtusum
Justicia americana
Lepidium campestre
Lepidium virginicum
Lycopus americanus
Maianthemum canadense
Mitchella repens
Mummenhoffia alliacea
Obolaria virginica
Oenothera gaura
Persicaria virginiana
Pycnanthemum tenuifolium
Sedum ternatum
Five petals
Achillea millefolium
Aegopodium podagraria
Anemone quinquefolia
Anemone virginiana
Apocynum androsaemifolium
Apocynum cannabinum
Arenaria serpyllifolia
Asclepias verticillata
Buglossoides arvensis
Calystegia sepium
Cerastium arvense
Cerastium fontanum
Cerastium glomeratum
Chaerophyllum tainturieri
Comandra umbellata
Conium maculatum
Cryptotaenia canadensis
Daucus carota
Ellisia nyctelea
Epigaea repens
Erigenia bulbosa
Euphorbia corollata
Fagopyrum esculentum
Fragaria virginiana
Galinsoga quadriradiata
Geum canadense
Hydatica petiolaris
Hydrophyllum canadense
Hydrophyllum virginianum
Ipomoea lacunosa
Ipomoea pandurata
Micranthes virginiensis
Mollugo verticillata
Monotropa uniflora
Myosotis macrosperma
Myosotis verna
Osmorhiza claytonii
Osmorhiza longistylis
Panax trifolius
Penstemon digitalis
Persicaria hydropiperoides
Persicaria sagittata
Phlox divaricata
Phlox subulata
Phytolacca americana
Polygonum aviculare
Rosa multiflora
Rubus allegheniensis
Rubus flagellaris
Rubus hispidus
Rubus occidentalis
Rubus pensilvanicus
Saponaria officinalis
Silene caroliniana
Silene latifolia
Silene stellata
Silene vulgaris
Solanum carolinense
Solanum ptychanthum
Stellaria graminea
Stellaria media
Stellaria pubera
Valerianella radiata
Verbascum blattaria
Verbena urticifolia
Viola canadensis
Viola primulifolia
Viola striata
Six petals
Allium canadense
Allium tricoccum
Anemone americana
Erythronium albidum
Maianthemum racemosum
Ornithogalum nutans
Ornithogalum umbellatum
Podophyllum peltatum
Tiarella cordifolia
Many petals
Ageratina altissima
Anemone americana
Anthemis arvensis
Cichorium intybus
Eclipta prostata
Erigeron annuus
Erigeron philadelphicus
Erigeron strigosus
Eurybia divaricata
Jeffersonia diphylla
Leucanthemum vulgare
Nymphaea odorata
Podophyllum peltatum
Sanguinaria canadensis
Sericocarpus asteroides
Symphyotrichum lanceolatum
Symphyotrichum lateriflorum
Symphyotrichum racemosum
Thalictrum pubescens
Thalictrum thalictroides
Pea-shaped petals
Hylodesmum pauciflorum
Lespedeza cuneata
Melilotus albus
Irregular
Acalypha rhomboidea
Agastache nepetoides
Ageratina aromatica
Antennaria neglecta
Antennaria parlinii
Antennaria plantaginifolia
Arnoglossum atriplicifolium
Conyza canadensis
Dicentra canadensis
Dicentra cucullaria
Dipsacus laciniatus
Erechtites hieraciifolius
Eupatorium hyssopifolium
Eupatorium perfoliatum
Eupatorium rotundifolium
Eupatorium serotinum
Eupatorium sessilifolium
Eupatorium torreyanum
Goodyera pubescens
Hedeoma pulegioides
Justicia americana
Lobelia inflata
Lonicera japonica
Melampyrum lineare
Mikania scandens
Monotropa uniflora
Nepeta cataria
Persicaria punctata
Platanthera lacera
Pseudognaphalium obtusifolium
Pycnanthemum incanum
Pycnanthemum muticum
Saururus cernuus
Spiranthes lacera
Thalictrum revolutum
Trifolium repens
Yellow or Orange
Four petals
Barbarea vulgaris
Brassica rapa
Chelidonium majus
Clematis ochroleuca
Cruciata pedemontana
Hypericum hypericoides
Ludwigia alternifolia
Oenothera biennis
Oenothera fruticosa
Oenothera pilosella
Five petals
Abutilon theophrasti
Agrimonia parviflora
Agrimonia pubescens
Anagallis arvensis
Asclepias tuberosa
Chamaecrista fasciculata
Chrysogonum virginianum
Duchesnea indica
Geum vernum
Geum virginianum
Hypericum canadense
Hypericum mutilum
Hypericum perforatum
Hypericum prolificum
Hypericum punctatum
Ludwigia peploides
Lysimachia ciliata
Lysimachia nummularia
Lysimachia quadrifolia
Portulaca oleracea
Potentilla canadensis
Potentilla norvegica
Potentilla recta
Potentilla simplex
Ranunculus abortivus
Ranunculus bulbosus
Ranunculus hispidus
Ranunculus recurvatus
Sedum sarmentosum
Verbascum blattaria
Verbascum thapsus
Viola pubescens
Six petals
Caulophyllum thalictroides
Erythronium americanum
Hypoxis hirsuta
Iris domestica
Iris pseudacorus
Nuphar advena
Polygonatum biflorum
Uvularia perfoliata
Many petals
Bidens aristosa
Bidens cernua
Coreopsis lanceolata
Coreopsis tinctora
Coreopsis verticillata
Euthamia graminifolia
Ficaria verna
Helenium autumnale
Helenium flexuosum
Helianthus angustifolius
Helianthus annuus
Helianthus decapetalus
Helianthus divaricatus
Helianthus laetiflorus
Helianthus mollis
Helianthus tuberosus
Heliopsis helianthoides
Hieracium gronovii
Hieracium paniculatum
Hieracium scabrum
Hieracium venosum
Krigia dandelion
Lactuca canadensis
Lactuca saligna
Lactuca serriola
Packera anonyma
Packera aurea
Pilosella caespitosa
Ratibida pinnata
Rudbeckia fulgida
Rudbeckia hirta
Rudbeckia lacinata
Rudbeckia triloba
Silphium asteriscus
Solidago rigida
Sonchus asper
Taraxacum officinale
Tussilago farfara
Verbesina alternifolia
Verbesina occidentalis
Youngia japonica
Pea-shaped petals
Lotus corniculatus
Medicago lupulina
Melilotus officinalis
Stylosanthes biflora
Trifolium aureum
Trifolium campestre
Trifolium dubium
Irregular
Agastache nepetoides
Bidens bipinnata
Bidens frondosa
Chrysosplenium americanum
Collinsonia canadensis
Corydalis flavula
Cypripedium parviflorum
Impatiens capensis
Impatiens pallida
Laportea canadensis
Lonicera japonica
Matricaria discoidea
Melampyrum lineare
Monarda punctata
Orontium aquaticum
Pedicularis canadensis
Pseudognaphalium obtusifolium
Senecio vulgaris
Thalictrum dioicum
Green or Brown
Three petals
Four petals
Galium circaezans
Galium trifolium
Five petals
Aralia nudicaulis
Asclepias viridiflora
Heuchera americana
Six petals
Brasenia schreberi
Medeola virginiana
Polygonatum biflorum
Irregular
Ambrosia artemisiifolia
Ambrosia trifida
Arisaema triphyllum
Boehmeria cylindrica
Conopholis americana
Epifagus virginiana
Epipactis helleborine
Erechtites hieraciifolius
Pedicularis canadensis
Platanthera lacera
Rumex crispus
Rumex obtusifolius
Saururus cernuus
Symplocarpus foetidus
Tipularia discolor
Urtica dioica