Common Name: Indian swampweed
Family: Acanthaceae
Common Synonyms: Justicia polysperma
USDA Hardiness Zone: 7b - 11
Growth Habit: Emergent Aquatic
Origin: India, Malaysia
FISC Category: 1
FDACS Listed Noxious Weed: Yes
Introduction Date: 1965
IFAS Assessment:
Perennial aquatic, mostly submersed, rooted. Square stem. Leaves opposite, variable color green to reddish, 8 cm long and 2 cm wide, broadest toward tip, joined at node by ciliate flange of tissue to 1.5 mm long. Flowers bluish white, small, solitary in upper leaf axils (almost hidden by the leaves). Fruit a narrow capsule with tiny round seeds.
Streams, springs, lakes, and ruderal sites, prefers flowing streams
Popular aquarium plant. Vouchered Broward north to Leon County. Established in some waterways since 1980s. Eradication unlikely.
**Follow herbicide labels: Only herbicides registered for application in water by EPA and FDACS may be applied to weeds growing in or near water.
Dave's Garden. 2013. PlantFiles: Hygrophila, Hygrophila polysperma. http://davesgarden.com/guides/pf/go/32039/. Accessed on December 10, 2013.
IFAS, Center for Aquatic and Invasive Plants. 2013. East Indian hygrophila.http://plants.ifas.ufl.edu/node/191. Accessed on December 2, 2013.
Langeland, K.A., H.M. Cherry, C.M. McCormick, K.C. Burks. 2008. Identification and Biology of Non-Native Plants in Florida's Natural Areas-Second Edition. IFAS Publication SP 257. University of Florida, Gainesville, Florida.
Vandiver VV. 1980. Hygrophila. Aquatics 2:4-11