Faculty Publications and Presentations

Publication Date


Document Type



Biology | Chemistry


Published in the Journal of Aquatic Plant Management, 31:227-231, 1993.


Giant salvinia (Salviniaceae) is a potentially serious aquatic weed that is native to Brazil. It has been reported in more than 20 countries, but is not established in the U.S. at this time. Mitchell and Tur (1975) reported that three years after the formation of the Kariba Reservoir in Africa, giant salvinia blanketed 21.5% or 1003 km2 of the reservoir surface area. Creagh (199111992) wrote, "A single small plant may grow to form a thick mat covering more than 100 sq. km. in just three months - choking lakes and waterways, reducing populations of aquatic plants and animals and in some countries threatening the livelihoods of ... thousands of people".

Dense mats of giant salvinia. interfere with rice cultivation, clog fishing nets, and disrupt access to water for humans, livestock, and wildlife (Mitchell 1979), and recreation, transportation, irrigation, hydroelectric generation, and flood control are also hampered (Holm et al. 1977). Thick mats of giant salvinia form large floating islands which support secondary and tertiary colonizing plants and fill in waterbodies (Thomas 1979).

Common names of S. molesta include giant salvinia, African pyle, and Kariba weed (Mitchell and Thomas 1972). These names allude to this species' relatively large size and to its successful invasion of Lake Kariba and other waters of Africa.

The plant was originally reported as a form of S. auriculata Aubl. It was later reclassified as S. molesta, based on details of the male sporocarps (Mitchell 1972). This review reports on the pertinent scientific literature concerning giant salvinia.