Swamp leather-flower
Clematis species grow throughout North America. In Florida, Wunderlin (2003) counts seven Clematis species, including one native only to Florida (endemic), and one as an occasional non-native escapee.
This one, swamp leather-flower is a vine. It is frequently found in floodplain forests and wet hammocks from northern counties south to mid-Florida. This species also grows throughout the southeastern U.S., and north to Missouri (Kartesz 1999). It blooms from spring to summer.