Table 1: First discovery of alien invasive species in various wetland and riverine systems in Botswana.

Salvinia Salvinia molesta Mitchell
Chobe River at  Kazungula: 1948
Kwando-Linyanti-Chobe Rivers: 1971
Okavango Delta: Xini - July 1986; Bodumatau -  July 1988; Gomoti - 1990; Abaqao/Mogohelo,  - August 1992; Xaxanaka on Maunachira - July 1992; Khwai - 1992;  Khwai at Mababe -April 2000; Dombo 1995; Santantadibe  at Ditshipi - November 2002 and at Sandibe - 2003; Mboroga feeder channel and Maunachira Hippo pool - January 2007;  Gadikwe and Xugana Lagoon - March 2008; Boro River - June 2010; Thamalakane - December 2012
Water Lettuce Pistia stratiotes L.
Absent in the Okavango Delta. First discovered in Chobe River in 1986 and after three months in Selinda Canal and Zibadianja Lagoon of Kwando River
Water hyacinth Eichhornia crassipes (Martius) Solms-Laubach
Absent in the Okavango Delta, Kwando-Linyanti-Chobe Rivers. However, found as an ornamental plant in few homes of Kasane village on 27 March 2002 and in Maun village close to the Okavango Delta in January 2016, confiscated the weed and destroyed.

Trans-boundary Limpopo River: First reported in May 2010 and its source of infestation is from Hartbeesport Dam and Crocodile River in South Africa.