There are also many species of tree frogs, and fish such as sturgeon and paddlefish.
In more elevated areas, fire is a natural process in the landscape, and has produced extensive areas of longleaf pine forest and wet savannas.
On Wednesday, the News & Observer published details about what investigators found in the home after carrying out a search warrant.
They took as evidence a 'white bedspread, a white sheet, and gray white comforter and several pillowcases that were all marred with an unknown red substance' - as well as an empty box of Coricidin Cold & Cough medicine, the same brand that Phelps said he took before the murder.
Louisiana slowly developed, over millions of years, from water into land, and from north to south.
The oldest rocks are exposed in the north, in areas such as the Kisatchie National Forest.
Investigators found red-stained sheets and an empty box of cold medicine at the North Carolina home where a man says he killed his wife in a medicated stupor.
Matthew James Phelps, 29, called 911 in the early hours of September 1, saying that he took cough medicine, had a dream and woke up to find his wife Lauren, also 29, dead. 'When police arrived on the scene, Lauren was still alive but mortally wounded.
He starts to sob as he adds: 'I can’t believe I did this. Her husband was taken into custody and is now facing first-degree murder charges in her death.Much of the state's lands were formed from sediment washed down the Mississippi River, leaving enormous deltas and vast areas of coastal marsh and swamp.These contain a rich southern biota; typical examples include birds such as ibis and egrets.The alluvial region includes low swamp lands, coastal marshlands and beaches, and barrier islands that cover about 20,000 square miles (52,000 km).This area lies principally along the Gulf of Mexico and the Mississippi River, which traverses the state from north to south for a distance of about 600 miles (1,000 km) and empties into the Gulf of Mexico; the Red River; the Ouachita River and its branches; and other minor streams (some of which are called bayous).