Chicago received its name from a dense growth of ramps near Lake Michigan in Illinois Country observed in the 17th century. The Chicago River was referred to by the plant's indigenous name, according to explorer Robert Cavelier, sieur de La Salle, and by his comrade, the naturalist and diarist Henri Joutel. The plant, called "shikaakwa" ("chicagou") in the language of local native tribes, was once thought to be "Allium cernuum", the nodding wild onion, but research in the early 1990s showed the correct plant was the ramp.