Illinois Flowers Information

Illinois has many species of violets.

The native violet is the Illinois state flower; the state has 22 types of violets along with a wide variety of other flowers that grow throughout the lengthy state of almost 400 miles. Certain flowers are under state and federal protection.

Types

Illinois has 332 endangered or threatened plant species, according to the Illinois Department of Natural Resources. Some native flowering plants that are not threatened in Illinois are prairie blazing star (Liatris pycnostachya), wild geranium (Geranium maculatum) and Virginia bluebells (Mertensia virginica). Spring bulbs include giant flowering onion (Allium giganteum), crocus (Crocus spp.) and common hyacinth (Hyacinthus orientalis).

Growing Conditions

Much of the state has a humid, continental climate with hot humid summers and cold winters. The southern tip of Illinois differs with a humid, subtropical climate that makes winters less harsh. Illinois spans three plant hardiness zones including U.S. Department of Agriculture plant hardiness zone 4b, with an average minimum temperature of minus 25 degrees Fahrenheit; zone 5, where the average minimum temperature reaches minus 20 F; and 6a, with its minus 10 F minimum temperature.

Habitats

Each flower species has specific needs that its habitat fulfills, such as soil requirements, water and lighting. This Midwestern state offers an assortment of habitats for flowers including lake or river shores, prairies, floodplains and river valleys or driftless areas.

References

• Illinois Department of Natural Resources: Checklist of Endangered or Threatened Animals and Plants of Illinois; Aug. 2010
• Office of Governor Pat Quinn--Regional Native Plant Species List
• United States National Arboretum: United States Department of Agriculture Plant Hardiness Zone Map
• University of Illinois Extension: Spring Flowering Bulbs
• Illinois Department of Natural Resources: Spring Woodland Wildflowers of Illinois