Illinois Bundleflower
Illinois Horse-gentian
Illinois Pondweed
Illinois Ticktrefoil
Indian Blanket
Indian Breadroot
Indian Goosegrass
Indian Heliotrope
Indian Jointvetch
Indian Lovegrass
Indian Mallow
Indian Paintbrush
Indian Plantain
Indian Ricegrass
Indian Rushpea
Indian Strawberry
Indian Woodoats
Indian-tobacco
Indiangrass
Indianhemp
Indianpipe
Indigo
Inflated Narrow-leaf Sedge
Inland Rush
Interior Ironweed
Intermediate Pepperweed
Iodanthus
Ipomopsis
Iris
Iron Ipomopsis
Ironweed
Italian Ryegrass
Ivyleaf Groundcherry
Ivyleaf Morning-glory
Ivyleaf Speedwell