Quick answer: 75 native Arkansas plants have a recorded bloom range that includes May.
75 species
- American basswood Tilia americana · 32 states
- American beautyberry Callicarpa americana · 10 states
- American holly Ilex opaca · 24 states
- American plum Prunus americana · 25 states
- Bigleaf magnolia Magnolia macrophylla · 5 states
- Black cherry Prunus serotina · 32 states
- Black maple Acer nigrum · 3 states
- Black walnut Juglans nigra · 33 states
- Blackhaw Viburnum prunifolium · 12 states
- Buffalograss Bouteloua dactyloides · 9 states
- Bur oak Quercus macrocarpa · 24 states
- Butterflyweed Asclepias tuberosa · 37 states
- Butternut Juglans cinerea · 5 states
- Canada wild rye Elymus canadensis · 18 states
- Cardinal flower Lobelia cardinalis · 37 states
- Common elderberry Sambucus nigra ssp. canadensis · 16 states
- Common persimmon Diospyros virginiana · 17 states
- Common yarrow Achillea millefolium · 31 states
- Coral bean Erythrina herbacea · 6 states
- Coral honeysuckle Lonicera sempervirens · 16 states
- Crossvine Bignonia capreolata · 5 states
- Cucumbertree Magnolia acuminata · 12 states
- Downy serviceberry Amelanchier arborea · 34 states
- Early azalea Rhododendron prinophyllum · 5 states
- Eastern hop-hornbeam Ostrya virginiana · 18 states
- Eastern purple coneflower Echinacea purpurea · 22 states
- Eastern red cedar Juniperus virginiana · 36 states
- Eastern red columbine Aquilegia canadensis · 36 states
- Eastern redbud Cercis canadensis · 30 states
- Eastern wahoo Euonymus atropurpureus · 2 states
- Flowering dogwood Cornus florida · 22 states
- Foxglove beardtongue Penstemon digitalis · 31 states
- Fragrant sumac Rhus aromatica · 14 states
- Fringed winecup Callirhoe digitata · 1 states
- Grayhead coneflower Ratibida pinnata · 12 states
- Green ash Fraxinus pennsylvanica · 23 states
- Honey locust Gleditsia triacanthos · 9 states
- Indian blanket Gaillardia pulchella · 18 states
- Lanceleaf coreopsis Coreopsis lanceolata · 28 states
- Large penstemon (shell-leaf beardtongue) Penstemon grandiflorus · 8 states
- Largeflower tickseed Coreopsis grandiflora · 2 states
- Lemon beebalm Monarda citriodora · 15 states
- Maypop passionflower Passiflora incarnata · 13 states
- Mexican hat Ratibida columnifera · 17 states
- Narrow-leaf coneflower Echinacea angustifolia · 9 states
- New Jersey tea Ceanothus americanus · 31 states
- Northern catalpa Catalpa speciosa · 9 states
- Ohio buckeye Aesculus glabra · 12 states
- Ozark witch-hazel Hamamelis vernalis · 1 states
- Pale purple coneflower Echinacea pallida · 9 states
- Pin oak Quercus palustris · 18 states
- Pink evening primrose Oenothera speciosa · 8 states
- Plains coreopsis Coreopsis tinctoria · 16 states
- Possumhaw Ilex decidua · 7 states
- Prairie redroot Ceanothus herbaceus · 1 states
- Rattlesnake master Eryngium yuccifolium · 6 states
- Roughleaf dogwood Cornus drummondii · 3 states
- Royal catchfly Silene regia · 1 states
- Rusty blackhaw viburnum Viburnum rufidulum · 12 states
- Scarlet oak Quercus coccinea · 17 states
- Shagbark hickory Carya ovata · 22 states
- Smooth sumac Rhus glabra · 34 states
- Spotted beebalm Monarda punctata · 14 states
- Sugar maple Acer saccharum · 28 states
- Swamp white oak Quercus bicolor · 9 states
- Sweetgum Liquidambar styraciflua · 22 states
- Virginia creeper Parthenocissus quinquefolia · 27 states
- Virginia springbeauty Claytonia virginica · 10 states
- White ash Fraxinus americana · 31 states
- White oak Quercus alba · 33 states
- White prairie clover Dalea candida · 1 states
- Wild blue Phlox divaricata · 32 states
- Willow oak Quercus phellos · 16 states
- Yaupon holly Ilex vomitoria · 7 states
- Yellow (Bush's) coneflower Echinacea paradoxa · 1 states