Waterpod is not especially common, but is native from Virginia to Florida to Louisiana (Kartesz, 1999). Four species of Hydrolea exist in Florida (Wunderlin, 2003). This particular species grows in the shallow waters of swamps and marshes from the northern counties south to the central peninsula of Florida; it flowers in the summer.
Waterpod is a medium-sized plant with blue axillary flowers and stout thorns. Don’t grab it without looking first. Its thick stems are covered with very visible hairs.