Because the state has a relatively uniform climate, plant species are distributed fairly generally throughout Indiana. There are 124 native tree species, including 17 varieties of oak, as well as black walnut, sycamore, and tulip tree (yellow poplar), the state tree. Fruit trees—apple, cherry, peach, and pear—are common. Local indigenous species—now reduced because of industrialization and urbanization—are the persimmon, black gum, and southern cypress along the Ohio River; tamarack and bog willow in the northern marsh; and white pine, sassafras, and pawpaw near Lake Michigan. American elderberry and bittersweet are common shrubs, while various jack-in-the-pulpits and spring beauties are among the indigenous wild flowers. The peony is the state flower. As of August 2003, Mead's milkweed and Pitcher's thistle were considered threatened and Short's goldenrod and running buffalo clover were considered endangered.
Although the presence of wolves and coyotes has been reported occasionally, the red fox is Indiana's only common carnivorous mammal. Other native mammals are the common cottontail, muskrat, raccoon, opossum, and several types of squirrel. Many waterfowl and marsh birds, including the black duck and great blue heron, inhabit northern Indiana, while the field sparrow, yellow warbler, and red-headed woodpecker nest in central Indiana. Various catfish, pike, bass, and sunfish are native to state waters.
The US Fish and Wildlife Service listed 25 Indiana animal species as threatened or endangered as of August 2003. Among these are the bald eagle, Indiana and gray bats, gray wolf, piping plover, and two species of butterfly.