Quick answer: 36 native Iowa plants have a recorded bloom range that includes March.
36 species
- American hornbeam Carpinus caroliniana · 29 states
- American sycamore Platanus occidentalis · 24 states
- Birdfoot violet Viola pedata · 14 states
- Black cherry Prunus serotina · 32 states
- Bloodroot Sanguinaria canadensis · 9 states
- Bur oak Quercus macrocarpa · 24 states
- Canada wild rye Elymus canadensis · 18 states
- Common blue violet Viola sororia · 21 states
- Eastern cottonwood Populus deltoides · 14 states
- Eastern leatherwood Dirca palustris · 5 states
- Eastern red cedar Juniperus virginiana · 36 states
- Eastern red columbine Aquilegia canadensis · 36 states
- Eastern redbud Cercis canadensis · 30 states
- Gray alder Alnus incana · 12 states
- Jack-in-the-pulpit Arisaema triphyllum · 14 states
- Longbract wild indigo (cream false indigo) Baptisia bracteata var. leucophaea · 5 states
- Mayapple Podophyllum peltatum · 18 states
- New Jersey tea Ceanothus americanus · 31 states
- Northern red oak Quercus rubra · 24 states
- Ohio buckeye Aesculus glabra · 12 states
- Pin oak Quercus palustris · 18 states
- Purple meadow-rue Thalictrum dasycarpum · 7 states
- Pussy willow Salix discolor · 9 states
- Quaking aspen Populus tremuloides · 24 states
- Red maple Acer rubrum · 30 states
- Red pine Pinus resinosa · 13 states
- River birch Betula nigra · 23 states
- Shagbark hickory Carya ovata · 22 states
- Silver maple Acer saccharinum · 18 states
- Smooth Solomon's seal Polygonatum biflorum · 13 states
- Swamp white oak Quercus bicolor · 9 states
- Virginia bluebells Mertensia virginica · 14 states
- White oak Quercus alba · 33 states
- Wild blue Phlox divaricata · 32 states
- Wild geranium Geranium maculatum · 11 states
- Winecup Callirhoe involucrata · 7 states