Nonindigenous Aquatic and Semi-Aquatic Plants in Freshwater Systems

Nonindigenous Aquatic Plants

Limnophila, Ambulia (Limnophila sessiliflora; Vahl) Blume.

This plant (Fig. 15) is native to Southeast Asia and to India (Schardt and Schmitz 1990). It was seemingly imported into Florida by the aquarium industry during the 1950's (Mahler 1980). It was first reported growing wild in Glades County (Long and Lakela 1971) and is now established in 10 public waters throughout the state (Schardt and Schmitz 1990). A review of this species was prepared by Gilbert (1984).

Limnophila produces a standing crop that is similar to the crop of hydrilla (Spencer and Bowes 1985) because most of its biomass is near the water surface where it can interfere with navigation and recreation (Schardt and Schmitz 1990). However, limnophila does not seem to colonize well in deeper-than-3-m water (Spencer and Bowes 1985) and prefers the quiet, shallow, and slightly acidic waters of lakes, rivers, and marshes (Mahler 1980). It can be submersed or emersed.

Reproduction of this species is sexual and asexual. The 10 limnophila populations reported in 1990 covered 19 ha of public waters. Limnophila only occasionally causes problems; an average of 2 ha--mostly in drainage canals--are controlled each year (Schardt and Schmitz 1990). Triploid grass carp reject limnophila, perhaps because of a toxin in the stem tissue (Mahler 1980).