Water Lettuce

Pistia stratiotes

Family:
Araceae

Lifecycle:
Perennial

Native or Introduced:
Native

Nutrient Removal Rating:
Medium-High

Wildlife Value:
Low

Invasiveness:
High

Rooted or Floating:
Floating

Site Requirements:
Full sun

Maximum Water Depth:
n/a

Plant Description:
Water lettuce is a perennial that often forms large floating colonies. Reproduction is vegetative and occurs through the use of stolons.

Leaves are light green to gray-green in color and measure 1 to 6 inches in length. They are spongy and have dense pubescence on the surface. Roots can grow up to 20 inches.

Inflorescences consist of a white to pale green spathe with a spadix that is shorter than the spathe. Small flowers are borne on the spadix. Flowering typically occurs from late summer to early winter.

Plants prefer to live in slow moving waters of canals, drainage ditches, ponds, and lakes. Water depths can range from 0 to 30 feet. It is not tolerant of freezing. This limits its expansion in much of the southeast.

Sources:

• Audlbach-Smith, C.A., deKozlowski, S.J. 1996. Aquatic and Wetland Plants of South Carolina. South Carolina Department of Natural Resources.
• Flora of North America (see link below)

Additional reading:

• USDA
• Flora of North America