Quick answer: 34 native Oklahoma plants have a recorded bloom range that includes August.
34 species
- American bellflower Campanulastrum americanum · 19 states
- Big bluestem Andropogon gerardii · 25 states
- Black-eyed Susan Rudbeckia hirta · 42 states
- Blue grama Bouteloua gracilis · 15 states
- Blue mistflower Conoclinium coelestinum · 26 states
- Buffalograss Bouteloua dactyloides · 9 states
- Butterflyweed Asclepias tuberosa · 37 states
- Cardinal flower Lobelia cardinalis · 37 states
- Common buttonbush Cephalanthus occidentalis · 23 states
- Common selfheal Prunella vulgaris · 2 states
- Common yarrow Achillea millefolium · 31 states
- Compass plant Silphium laciniatum · 11 states
- Dotted blazing star Liatris punctata · 10 states
- Eastern purple coneflower Echinacea purpurea · 22 states
- Fire pink Silene virginica · 8 states
- Indian blanket Gaillardia pulchella · 18 states
- Indiangrass Sorghastrum nutans · 19 states
- Little bluestem Schizachyrium scoparium · 23 states
- Maximilian sunflower Helianthus maximiliani · 3 states
- Mexican hat Ratibida columnifera · 17 states
- Orange coneflower Rudbeckia fulgida · 2 states
- Partridge pea Chamaecrista fasciculata · 13 states
- Pink-scale blazing star Liatris elegans · 5 states
- Prairie blazing star Liatris pycnostachya · 16 states
- Rocky Mountain bee plant Peritoma serrulata · 22 states
- Rough coneflower Rudbeckia grandiflora · 1 states
- Scarlet sage Salvia coccinea · 3 states
- Seaside alder Alnus maritima · 2 states
- Sideoats grama Bouteloua curtipendula · 25 states
- Smooth sumac Rhus glabra · 34 states
- Spotted beebalm Monarda punctata · 14 states
- Switchgrass Panicum virgatum · 24 states
- Western ironweed Vernonia baldwinii · 1 states
- Winged sumac Rhus copallinum · 11 states