Azolla caroliniana (Willd.) "Ponds from Henderson and Peoria counties
southward. Infrequent." (P.) "Since 1857 not found again in the
region of our local flora." _Brendel_ in Flora Peoriana. "In a
pond near South Chicago, 1886. So far as known this is the only
locality where this species has been found within our limits."
_Higley_ and _Raddin_.