Tape Grass

Vallisneria americana

Vallisneria americana, commonly known as tape grass or "wild celery", is a submersed vascular plant similar to seagrass that lives in fresher water. Tape grass is stoloniferous, meaning multiple clonal plants can grow from a single stolon, or "runner", extending horizontally beneath the sediment (Lovett-Doust and Laporte 1991). Individual V. americana plants are either male or female and are capable of sexual or aesexual reproduction.  During flowering periods, male flowers are released at the water surface and use surface tension to reach and pollinate female flowers. 

Like other types of submerged aquatic vegetation (SAV), tape grass often forms the basis of extremely productive estuarine ecosystems (Kraemer et al. 1999).  Besides stabilizing sediment and decreasing erosion, tape grass also provides food for aquatic animals like snails and manatees. Dense meadows can also create complex habitat structure that is used as cover by juvenile fish and other important species.

While most seagrasses are considered "euhaline" (thriving in higher salinities), tape grass is an "oligohaline" (low salinity) species. Though salt-tolerant, tape grass can experience slowed growth or death at salinities above 6-15 ppt (Haller 1974, Doering et al. 1999). In the Caloosahatchee River, tape grass is often stressed by fluctuations in salinity and light availability due to variable freshwater input between wet and dry seasons (Zieman and Zieman 1989). Diversion of freshwater flows from Lake Okeechobee for human and agricultural use exacerbates these effects by limiting freshwater influx and increasing saltwater intrusion in tape grass habitat.  The resulting exposure to higher salinities can lead to the degradation of V. americana communities and the services they provide.

The shaded area of the graph represents the optimal salinity range of 0-10 for healthy tape grass.