About Hydrocharis spongia Bosc
Hydrocharis spongia Bosc, commonly known as the American frogbit or the American spongeplant, is a species of flowering plant in the family Hydrocharitaceae. It is native to the central and southeastern United States, where it grows in the Lower Mississippi Valley as far north as Illinois, and on the Southern Coastal Plain from Texas to Delaware. It is occasionally found outside this native range as a waif. It grows in slow-moving water of streams, bayous, and lakes, at elevations ranging from sea level up to 100 meters. This species is a herbaceous plant that can grow up to 50 cm long. It produces heart-shaped or nearly rounded leaves that are either floating or emersed, with diameters between 1–3 inches (2–7 cm). Two different leaf forms often occur on the same individual: floating leaves have a thick layer of spongy aerenchyma on their underside, while emersed leaves do not have this aerenchyma. Plants are mostly dioecious, and sometimes monoecious. Flowering occurs in summer and fall, mostly on individuals that bear emersed leaves. Fruits that develop from pistillate flowers are 4 to 12 mm in diameter. After pollination, the peduncle curves downward to push the developing fruit below the water surface.
