Quick answer: 33 native Oklahoma plants have a recorded bloom range that includes March.
33 species
- American elm Ulmus americana · 4 states
- American sycamore Platanus occidentalis · 24 states
- Birdfoot violet Viola pedata · 14 states
- Black oak Quercus velutina · 2 states
- Blackjack oak Quercus marilandica · 3 states
- Bur oak Quercus macrocarpa · 24 states
- Canada wild rye Elymus canadensis · 18 states
- Chinkapin oak Quercus muehlenbergii · 14 states
- Common blue violet Viola sororia · 21 states
- Common hoptree Ptelea trifoliata · 12 states
- Dwarf crested iris Iris cristata · 1 states
- Eastern red cedar Juniperus virginiana · 36 states
- Eastern red columbine Aquilegia canadensis · 36 states
- Eastern redbud Cercis canadensis · 30 states
- Fringed bluestar Amsonia ciliata · 2 states
- Loblolly pine Pinus taeda · 14 states
- Mexican plum Prunus mexicana · 4 states
- Ohio buckeye Aesculus glabra · 12 states
- Pincushion daisy (perfumeballs) Gaillardia suavis · 1 states
- Pink evening primrose Oenothera speciosa · 8 states
- Possumhaw Ilex decidua · 7 states
- Post oak Quercus stellata · 9 states
- River birch Betula nigra · 23 states
- Sassafras Sassafras albidum · 22 states
- Scarlet sage Salvia coccinea · 3 states
- Shortleaf pine Pinus echinata · 9 states
- Silver maple Acer saccharinum · 18 states
- Slippery elm Ulmus rubra · 2 states
- Texas bluebonnet (state flower) Lupinus texensis · 2 states
- Three-flower melic grass Melica nitens · 1 states
- Wild blue Phlox divaricata · 32 states
- Wild hyacinth (Atlantic camas) Camassia scilloides · 1 states
- Winecup Callirhoe involucrata · 7 states