Botanical Name: Justicia ovata.

Common Names: Looseleaf Waterwillow

Plant type: Perennial herb

Zone: Naturally found in FL, GA, AL, IL, SC, LA, MS, OK, AK, TN, NC, KY, and MI. (See link below.)

Light: Sun

Size: Grows to 18"

Water: Average water needs.

Soil: Wet soil; found in wet ditches and wetlands, swamps and along rivers and streams

Propagation: Root divisions

Bloom: Lavender - purple

Note: Host plant for Seminole Texan Crescent Anthanassa texana seminole

More information:
Florida Butterfly Caterpillars and Their Host Plants by Marc C. Minno, Jerry F. Butler, and Donald W. Hall. For Florida butterfly caterpillar and host plant information, we recommend this book above all others.
USDA Plant Profile