starting with the flower's color or ◯∩ ⚮⛛✤❀✽ ♆  configuration :  if color-vision deficient CVD, start here

with petals / tepals / sepals / bracts that are colored:
❀ white    
❀ beige    
❀ tan        
❀ brown   

❀ red       
❀ orange 
❀ yellow 
❀ gold     

❀ green   
❀ cyan     
❀ blue      
❀ violet    
❀ pink       
❀ magenta

cluster of small flowers, shape=◯ round

❀ white    
❀ beige    

❀ red       
❀ orange 
❀ green   
❀ cyan     
❀ blue      
❀ violet    
❀ pink       
❀ magenta

single blossom, radial symmetry with ⚮ 2 equal parts ( ⚮ two-fold rotational symmetry)

❀ white    
❀ beige    

❀ pink       
❀ magenta

single blossom,  radial  symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)

❀ white    
❀ beige    

❀ yellow 
❀ gold     

❀ green   
❀ cyan     
❀ blue      
❀ violet    
❀ pink       
❀ magenta

single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

❀ white    
❀ beige    

❀ red       
❀ orange 
❀ yellow 
❀ gold     

❀ green   
❀ cyan     
❀ blue      
❀ violet    
❀ pink       
❀ magenta

❀ white       ❀ beige    

and each flowerhead contains a:
cluster of small flowers[?], shape=◯ round
cluster of small flowers,  shape=∩ elongated

single blossom, radial symmetry with ⚮ 2 equal parts ( ⚮ two-fold rotational symmetry)
single blossom,  radial  symmetry with ⛛ 3 equal parts (⛛three-fold rotational symmetry)
single blossom,  radial  symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)
single blossom,  radial  symmetry with ❀ 5 equal parts ( ❀ five-fold rotational symmetry)
single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

white beige cluster of small flowers, shape=◯ round

🚶︎ adult-high woody shrub, clusters of very-small flowers with 5 petals=white around white or yellow stamens, 20% of a sphere, leaves=compound
elderberry  genus Sambucus

shrub/understory tree, flowers early in the growing season, in clusters each with 5 long skinny white petals
serviceberry  genus Amelanchier

very-tall herbaceous perennial, huge clusters of very-small white flowers, 20% of a sphere, leaves=huge, wide, ♧ lobed
like Queen Anne's lace  Daucus carota  on steroids
X✋︎ ☠︎ giant hogweed  Heracleum mantegazzianum ☠︎ ✋︎X

tall herbaceous perennial, huge clusters of very-small white flowers, 20% of a sphere, leaves=huge, wide, ♧ lobed
like Queen Anne's lace  Daucus carota  on steroids
X✋︎ ☠︎ cow parsnip  Heracleum maximum ☠︎ ✋︎X

waist-high herbaceous perennial, clusters of very-small flowers with 5 petals=white around a white center, 20% of a sphere, leaves=simple, very narrow
whorled milkweed  Asclepias verticillata

white beige cluster of small flowers, shape=∩ elongated

herbaceous;  pink or white irregular clusters of ✤ four-petal flowers, looking like cotton candy
queen of the prairie  Filipendula rubra

herbaceous;  white or yellow-green very-tall and -thin clusters of five-petal flowers late in growing season;  stems segmented like bamboo
Japanese knotweed  Fallopia japonica

shrub;  small white 5 petals with a large green center, that turn into green then dark-purple fruit
American pokeweed  Phytolacca americana

tree;  5 petals;  leaves=short (<10 cm) (<4 in), firm, leathery, broad midrib
◼︎🍒︎ black cherry  Prunus serotina

tree;  5 petals;  leaves=short (<10 cm) (<4 in), teeth curve toward base
🍒︎ chokecherry  Prunus virginiana

white beige single blossom, radial symmetry with ⚮ 2 equal parts ( ⚮ two-fold rotational symmetry)

2-sided white outer- and inner-petals
Asian bleeding-heart  Lamprocapnos spectabilis 'Alba'

white beige single blossom,  radial  symmetry with ⛛ 3 equal parts (⛛three-fold rotational symmetry)

3 striking equally-spaced petals (white, yellow, green, red or pink/magenta) surrounded by
3 sepals (◼︎◼︎ green or reddish) surrounded by
3 equally-spaced ╤ horizontal leaves, halfway between your ankle and knee
trillium  genus Trillium

3 striking equally-spaced ◼︎◼︎ white petals surrounded by
3 sepals (◼︎◼︎ green or reddish), above
3 equally-spaced ╤ horizontal leaves, halfway between your ankle and knee
◼︎ white trillium  Trillium grandiflorum

white beige single blossom,  radial  symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)

tree;  very large blossoms=white, pink or green;  opposite branching
dogwood  genus Cornus

tree, very small blossoms=white;  alternate branching
autumn olive  Elaeagnus umbellata

knee-high herb;  very small blossoms=white
garlic mustard  Alliaria petiolata

knee- to head-high herb;  pink or white irregular clusters of ✤ four-petal flowers, looking like cotton candy
queen of the prairie  Filipendula rubra

white beige single blossom,  radial  symmetry with ❀ 5 equal parts ( ❀ five-fold rotational symmetry)

low groundcover, herbaceous, or understory tree
full-sized tree

low groundcover, herbaceous, or understory tree

ankle-high groundcover;  flowers have yellow center, leaves have 3 leaflets and ▲▲ teeth
🍓︎ strawberry  genus Fragaria

knee- to ankle-high groundcover;  flowers=white with pink lines
Virginia springbeauty  Claytonia virginica

waist-high herbaceous perennial;  clusters of very-small flowers with 5 petals=white around a white center, 20% of a sphere;  leaves=simple, very narrow
whorled milkweed  Asclepias verticillata

waist-high herbaceous perennial;  single-flower petals=blue, violet, pink, red or white;  leaves=🍂︎ non-lobed
phlox  genus Phlox

shrub/understory tree;  flowers early in the growing season, in clusters each with 5 long skinny white petals
serviceberry  genus Amelanchier

full-sized tree

no thorn-like twigs;  leaves=🍂︎ non-lobed, ▲▲ toothed, each lateral vein terminates in ▴▴▴ multiple teeth, thin, hairless
🍒︎ pin cherry  Prunus pensylvanica

no thorn-like twigs;  leaves=🍂︎ non-lobed, ▲▲ toothed, teeth curve toward base, leaves=short (<10 cm) (<4 in);  clusters of flowers with 5 petals
🍒︎ chokecherry  Prunus virginiana

thorn-like twigs;  leaves=🍂︎ non-lobed, undersurface=​wooly hair
🍎︎ common apple  Malus pumila

thorn-like twigs;  leaves=🍂︎ non-lobed, tip=long tapering, undersurface=vein network intricate
American plum  Prunus americana

thorn-like twigs;  leaves=somewhat-♧-lobed;  twigs, petioles and leaf undersurface=​woolly
🍎︎ prairie crabapple  Malus ioensis

thorn-like twigs;  leaves=somewhat--lobed;  twigs and leaves=not woolly
🍎︎ wild crabapple  Malus coronaria

white beige single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

6 white petals (extending out, curled back, or 3 of each);  leaves=ankle-high, two-color (gray and dark-green)
◼︎ white trout lily  Erythronium albidum

6 white petals, hidden under two large ╤ horizontal lobed leaves, knee- to boot-top-high;  plants grouped together in a forest, only visible early in growing season
mayapple  Podophyllum peltatum

8–10–12 white petals (4 smaller petals on top, 4 bigger ones behind, defining a square), yellow center;  ankle-high;  when plant pulled up, roots drip red sap
bloodroot  Sanguinaria canadensis

many petals, yellow center
common daisy  Bellis perennis

❀ red       

and each flowerhead contains a:
cluster of small flowers[?], shape=◯ round
cluster of small flowers,  shape=∩ elongated

single blossom, radial symmetry with ⛛ 3 equal parts (⛛three-fold rotational symmetry)
single blossom,  radial  symmetry with ❀ 5 equal parts ( ❀ five-fold rotational symmetry)
single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

single blossom,  ♆ bilateral (🪞 mirror) ( face-like) symmetry

red cluster of small flowers, shape=◯ round

tree;  very-showy, small blossoms, appear early in growing season—often before leaves
◼︎ 🍁︎ red maple  Acer rubrum

herbaceous (waist-high);  very-showy, large combined blossoms, stem shape=◼︎ square
◼︎ 🐝︎ scarlet beebalm  Monarda didyma

red cluster of small flowers,  shape=∩ elongated

size and shape of small ice cream cone, inverted above branch, deep-red (fruit) or yellow-green (flower);  small tree
staghorn sumac  Rhus typhina

elongated clusters of red flowers with ♆ ☹ bilateral symmetry[?];  herbaceous plant
cardinal flower  Lobelia cardinalis

red single blossom, radial symmetry with ⛛ 3 equal parts (⛛three-fold rotational symmetry)

3 striking equally-spaced petals (white, yellow, green, red or pink/magenta) surrounded by
3 sepals (◼︎◼︎ green or reddish) surrounded by
3 equally-spaced ╤ horizontal leaves, halfway between your ankle and knee
trillium  genus Trillium

deep-red, right at ground level (dig through leaf-litter to see it)
wild ginger  genus Asarum

red single blossom,  radial  symmetry with ❀ 5 equal parts ( ❀ five-fold rotational symmetry)

deep-red, along a ☙ vine
◼︎ pale swallow-wort  Cynanchum rossicum

red single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

very-showy, large combined blossoms, herbaceous, stem shape=◼︎ square
◼︎ 🐝︎ scarlet beebalm  Monarda didyma

red single blossom, ♆ bilateral (🪞 mirror) ( face-like) symmetry

elongated clusters of red flowers with ♆ ☹ bilateral symmetry;  herbaceous plant
cardinal flower  Lobelia cardinalis

❀ yellow    ❀ gold     

reminds Kelly D. Norris of 🌐︎ Northern Hemisphere August (🌐︎ Southern Hemisphere February).
Continue with whether each flowerhead contains a:
cluster of small flowers[?], shape=∩ elongated

single blossom, radial symmetry with ⛛ 3 equal parts (⛛three-fold rotational symmetry)
single blossom,  radial  symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)
single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

yellow gold cluster of small flowers, shape=∩ elongated

tree;  large flower cluster above branch, yellow-to-green;  crushed leaflets (mash well) 👃︎ smell like 🥜︎ peanut butter or rotting cashews
tree of heaven (ToH)  Ailanthus altissima

small tree;  flower cluster size and shape of very-large ice cream cone, inverted above branch, yellow-green (flower) or deep-red (fruit)
staghorn sumac  Rhus typhina

herbaceous;  gold very-tall and -thin clusters of many-petal flowers late in growing season
goldenrod  genus Solidago

herbaceous;  white or yellow-green very-tall and -thin clusters of five-petal flowers late in growing season;  stems segmented like bamboo
Japanese knotweed  Fallopia japonica

yellow gold single blossom,  radial  symmetry with ⛛ 3 equal parts (⛛three-fold rotational symmetry)

3 striking equally-spaced petals (white, yellow, green, red or pink/magenta) surrounded by
3 sepals (◼︎◼︎ green or reddish) surrounded by
3 equally-spaced ╤ horizontal leaves, halfway between your ankle and knee
trillium  genus Trillium

3 striking equally-spaced ◼︎ yellow petals surrounded by
3 ◼︎ green sepals, above
3 equally-spaced ╤ horizontal variegated leaves (two colors—green and gray-green), halfway between your ankle and knee
◼︎ yellow trillium  Trillium luteum

yellow gold single blossom,  radial  symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)

small tree;  4 very-small yellow to yellow-green petals (actually sepals, after longer outer petals fall off);  flowers very late in growing season, long into dormant season
American witch-hazel  Hamamelis virginiana

woody shrub, waist- to head-high;  flowers=very-showy, appear early in growing season—often before leaves
forsythia  genus Forsythia

herbaceous, boot-top-high;  petals do not overlap
greater celandine poppy  Chelidonium majus

herbaceous, boot-top-high;  petals overlap
celandine poppy  Stylophorum diphyllum

yellow gold single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

6 yellow petals (extending out, curled back, or 3 of each);  leaves=ankle-high, two-color (gray and dark-green)
◼︎ yellow trout lily or ◼︎ ◼︎ yellow dogtooth violet  Erythronium americanum

4 or 8[?] very-thin crinkled petals, yellow to yellow-green (inner) and school-bus-yellow (outer);  flowers very late in growing season, long into dormant season
American witch-hazel  Hamamelis virginiana

7–8–11 petals, aquatic
lesser celandine or fig buttercup  Ficaria verna

many yellow petals, yellow center, ankle-high
dandelion  genus Taraxacum

many yellow petals, roughly head-high
🌻︎ sunflower  genus Helianthus

❀ cyan        ❀ blue         ❀ violet    

and each flowerhead contains a:
cluster of small flowers[?], shape=◯ round
cluster of small flowers,  shape=∩ elongated

single blossom, radial symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)
single blossom,  radial  symmetry with ❀ 5 equal parts ( ❀ five-fold rotational symmetry)
single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

single blossom,  ♆ bilateral (🪞 mirror) ( face-like) symmetry

cyan blue violet cluster of small flowers, shape=◯ round

light purple or pink around white center, 40% of sphere, 👃︎ subtle smell of vanilla
♒︎ swamp milkweed  Asclepias incarnata

cyan or purple, connected together into a trumpet shape, clustered irregularly
Virginia bluebell  Mertensia virginica

violet, very showy, large combined blossoms, herbaceous, stem shape=◼︎ square
🐝︎ bee balm / bergamot / horsemint  genus Monarda

violet
crown vetch  Securigera varia

cyan blue violet cluster of small flowers, shape=∩ elongated

violet, each flower has bilateral (🪞 mirror) ( face-like) symmetry[?];  ☙ vine;  leaves=🌿︎ compound 3 leaflets
kudzu  Pueraria montana

violet, each flower has bilateral (🪞 mirror) ( face-like) symmetry[?];  herb;  leaves=❋ whorled five-to-28 leaflets
lupine  genus Lupinus

violet
crown vetch  Securigera varia

violet
◼︎ mint/sage  family Lamiaceae

cyan blue violet single blossom, radial symmetry with ✤ 4 equal parts ( ✤ four-fold rotational symmetry)

usually lavender or purple, sometimes white or pink, or mixed in cultivars
dame's rocket  Hesperis matronalis

cyan blue violet single blossom,  radial  symmetry with ❀ 5 equal parts ( ❀ five-fold rotational symmetry)

leaves=🍂︎ non-lobed;  petals=purple (very-dark) or black
◼︎ black swallow-wort  Cynanchum louiseae

leaves=🍂︎ non-lobed;  petals=cyan, with yellow center;  low (ankle-high)
forget-me-not  genus Myosotis

leaves=🍂︎ non-lobed;  petals=cyan or purple, connected together into a trumpet shape, clustered irregularly
Virginia bluebell  Mertensia virginica

leaves=🍂︎ non-lobed;  petals=blue, violet, pink, red or white
phlox  genus Phlox

leaves=5-♧-lobed;  petals=violet, pink, rarely white;  low (ankle-high)
wild geranium  Geranium maculatum

cyan blue violet single blossom,  radial  symmetry with ✽💮︎❁ 6+ equal parts (✽💮︎❁ six+-fold rotational symmetry)

violet, very showy, large combined blossoms, herbaceous, stem shape=◼︎ square
🐝︎ bee balm / bergamot / horsemint  genus Monarda

cyan blue violet single blossom, ♆ bilateral (🪞 mirror) ( face-like) symmetry

violet, leaves=❋ whorled five-to-28 leaflets
lupine  genus Lupinus

Learn more about ⚘ ❀ flowers

Uses by native peoples
(Ethnobotany database)

plant terminology   Flower structure, flower clusters (inflorescences), floral formula.

Flora of North America Wikipedia