60 wildflowers were recorded blooming in Texas in May in our iNaturalist sample; 19 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top wildflowers in May

Whitemouth Dayflower

Purple Passionflower
American basketflower
Turk's cap

Texas Thistle

Firewheel
Green Antelopehorns

Chinese privet
Upright Prairie Coneflower
Purple Groundcherry

Texas bindweed

Antelopehorn Milkweed
All wildflowers blooming in Texas in May
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Whitemouth Dayflower | Commelina erecta | Spiderworts | 963 | May (peak) |
| 2 | Purple Passionflower | Passiflora incarnata | Passionfruit Family | 871 | May (peak) |
| 3 | American basketflower | Plectocephalus americanus | Sunflowers, Daisies, Asters, and Allies | 667 | Jun (rising) |
| 4 | Turk's cap | Malvaviscus arboreus | Mallow and Hibiscus Family | 641 | May (peak) |
| 5 | Texas Thistle | Cirsium texanum | Sunflowers, Daisies, Asters, and Allies | 611 | May (peak) |
| 6 | Firewheel | Gaillardia pulchella | Sunflowers, Daisies, Asters, and Allies | 529 | Apr (past peak) |
| 7 | Green Antelopehorns | Asclepias viridis | Dogbane Family | 527 | Apr (past peak) |
| 8 | Chinese privet | Ligustrum sinense | olive family | 512 | Apr (past peak) |
| 9 | Upright Prairie Coneflower | Ratibida columnifera | Sunflowers, Daisies, Asters, and Allies | 510 | May (peak) |
| 10 | Purple Groundcherry | Quincula lobata | nightshade family | 503 | Apr (past peak) |
| 11 | Texas bindweed | Convolvulus equitans | bindweed family | 472 | Apr (past peak) |
| 12 | Antelopehorn Milkweed | Asclepias asperula | Dogbane Family | 461 | Apr (past peak) |
| 13 | Purple Pleatleaf | Alophia drummondii | iris family | 460 | May (peak) |
| 14 | black-eyed Susan | Rudbeckia hirta | Sunflowers, Daisies, Asters, and Allies | 459 | May (peak) |
| 15 | Silverleaf Nightshade | Solanum elaeagnifolium | nightshade family | 429 | Apr (past peak) |
| 16 | Lemon Beebalm | Monarda citriodora | Mint Family | 427 | May (peak) |
| 17 | Plains Coreopsis | Coreopsis tinctoria | Sunflowers, Daisies, Asters, and Allies | 400 | May (peak) |
| 18 | Eastern Coral Bean | Erythrina herbacea | Legumes | 398 | May (peak) |
| 19 | Chinese Tallow | Triadica sebifera | Spurge Family | 395 | May (peak) |
| 20 | Texas bluebonnet | Lupinus texensis | Legumes | 388 | Mar (past peak) |
| 21 | Clasping Coneflower | Rudbeckia amplexicaulis | Sunflowers, Daisies, Asters, and Allies | 385 | May (peak) |
| 22 | Drummond's rain lily | Zephyranthes drummondii | amaryllis, onions, and allies | 357 | Apr (past peak) |
| 23 | Lantana | Lantana strigocamara | Verbena Family | 352 | Apr (past peak) |
| 24 | Pearl Milkweed | Matelea reticulata | Dogbane Family | 330 | May (peak) |
| 25 | Musk Thistle | Carduus nutans | Sunflowers, Daisies, Asters, and Allies | 327 | May (peak) |
| 26 | Pinkladies | Oenothera speciosa | evening primrose family | 317 | Apr (past peak) |
| 27 | Straggler Daisy | Calyptocarpus vialis | Sunflowers, Daisies, Asters, and Allies | 281 | Apr (past peak) |
| 28 | Yellow Passionflower | Passiflora lutea | Passionfruit Family | 277 | Jun (rising) |
| 29 | Turkey Tangle Frogfruit | Phyla nodiflora | Verbena Family | 248 | Apr (past peak) |
| 30 | American black elderberry | Sambucus canadensis | elder family | 247 | May (peak) |
| 31 | Winecup Mallow | Callirhoe involucrata | Mallow and Hibiscus Family | 236 | Apr (past peak) |
| 32 | Engelmann daisy | Engelmannia peristenia | Sunflowers, Daisies, Asters, and Allies | 214 | Apr (past peak) |
| 33 | Butterfly Milkweed | Asclepias tuberosa | Dogbane Family | 211 | May (peak) |
| 34 | Smooth Sumac | Rhus glabra | Cashew Family | 208 | May (peak) |
| 35 | Dakota mock vervain | Glandularia bipinnatifida | Verbena Family | 206 | Apr (past peak) |
| 36 | Texas Skeleton Plant | Lygodesmia texana | Sunflowers, Daisies, Asters, and Allies | 200 | May (peak) |
| 37 | Scarlet Pimpernel | Lysimachia arvensis | primrose family | 190 | Apr (past peak) |
| 38 | Gregg's tube tongue | Justicia pilosella | Acanthus Family | 186 | Apr (past peak) |
| 39 | Zizotes milkweed | Asclepias oenotheroides | Dogbane Family | 185 | Sep (rising) |
| 40 | Roughleaf Dogwood | Cornus drummondii | Dogwood family | 171 | Apr (past peak) |
| 41 | Tievine | Ipomoea cordatotriloba | bindweed family | 170 | Sep (rising) |
| 42 | Texas lantana | Lantana urticoides | Verbena Family | 169 | Apr (past peak) |
| 43 | Field Bindweed | Convolvulus arvensis | bindweed family | 154 | May (peak) |
| 44 | American germander | Teucrium canadense | Mint Family | 146 | Jun (rising) |
| 45 | Mexican palo verde | Parkinsonia aculeata | Legumes | 144 | Apr (past peak) |
| 46 | Tropical sage | Salvia coccinea | Mint Family | 142 | Apr (past peak) |
| 47 | Cowpen Daisy | Verbesina encelioides | Sunflowers, Daisies, Asters, and Allies | 141 | Apr (past peak) |
| 48 | Common Sunflower | Helianthus annuus | Sunflowers, Daisies, Asters, and Allies | 140 | Jun (rising) |
| 49 | Blackfoot Daisy | Melampodium leucanthum | Sunflowers, Daisies, Asters, and Allies | 137 | Apr (past peak) |
| 50 | Texas Paintbrush | Castilleja indivisa | broomrape family | 137 | Apr (past peak) |