Description: Leaves are flashy and arranged in a rosette. They measure 0.75-6 in. (2-15 cm) in length. The leaves are green to grayish-green and have dense white hairs and parallel veins on their surface. As its common name indicates, the plant resembles a floating head of lettuce.

 

Ecological Threat:  forms extensive mats that can block navigational channels, impede water flow in irrigation and flood control canals, and disrupt submersed animal and plant communities. It has been placed on prohibited plant lists in Florida, Louisiana, Mississippi, and Texas.

 

Biology & Spread:  The hydrosoil under a Pistia stratiotes infestation was shown to hold 4,196 seeds/m2. Mature seeds had an 84% germination rate.

 

In Oklahoma:  This plant can still be legally purchased in Oklahoma.  The only known wild populations were found at Pretty Water Lake at Sapulpa.

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Management: Aquatic Weed Management, OSU Extension Factsheet