Common name: giant water sensitive plant

Synonyms and Other Names: Botswana wonder, water pea, golden Botswana, giant sensitive plant, large leafed sensitive plant

Identification: According to Verdcourt (2000):

Habit: perennial, floating, aquatic forb

Stems/Roots: hollow to spongy stems and dense adventitious roots.

Leaves: pinnately compound leaves up to 8 cm with 16-26 pairs of leaflets; leaflets 9-25 mm long, typically glabrous, blue-green in color; margin entire or finely serrate. Leaves close slowly when touched, as in Mimosa spp.

Flowers: solitary, yellow, papilionacious flowers in the leaf axils.

Fruits/Seeds: segmented loment (indehiscent legume) is straight or slightly curved and 1.5-5 cm long with a ridge around the margin.

Look-a-likes: other jointvetch species (Aeschynomene spp.) in the US have similar leaves and flowers, but are not aquatic, floating plants.

Size: 1 to 4.5 m total length (Verdcourt 2000)

Native Range: Southern Africa (Angola, Botswana, Democratic Republic of the Congo, Namibia, Tanzania, Zambia) (Verdcourt 2000)

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology:

Habitat: slow-moving rivers, ponds, and floodplains (Verdcourt 2000).

Tolerances: reported hardy in USDA zones 8-11 (Florida Aquatic 2008, Pond Megastore Wholesale Waterlilies Department 2017) where average annual minimum temperatures range between -12° and 4.4° C (10° to 40° F) (USDA-ARS 2012).

Community: associated with other aquatic and riparian plant species in native Botswana and Namibia, such as Ceratophyllum, Cyperus, Ludwigia, Mikania, Mimosa, Nymphaea, Persicaria, Phragmites, and Schoenoplectus (Ellery and Tacheba 2003, Strohbach 2013).

Means of Introduction: This plant is available for sale in the US as an ornamental pond plant through the internet and various nurseries and catalogs (Allen et al. 2017). Improper disposal or intentional release by a home-owner is the most likely initial pathway.

Status: The status of the Lousiana population is unknown; a waste water treatment facility just downstream of Lake Arrow Wood may serve to reduce the number of viable seeds or plant fragments dispersing downstream to the Abita River (K. Rust, pers. comm. 2007). The SW Florida population is established and has likely spread from Lake Dosson into neighboring Sunshine Lake (L. Holland, pers. comm. 2017).

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: The habit, leaves and fruit match specimens from native range. Sample or detailed photograph of flower required to confirm to species (G. Lewis, pers. comm. 2007).

References: (click for full references)

Agricultural Research Service, U.S. Department of Agriculture (USDA-ARS). 2012. USDA Plant Hardiness Zone Map. http://planthardiness.ars.usda.gov. Accessed on 08/28/2017.

Allen, K., R.T. Isaacson, C. Aho, S. Cross, and C.R. Jensen. 2017. Aeschynomene fluitans | Plant Information Online. https://plantinfo.umn.edu/node/1445007. Accessed on 08/28/2017.

Ellery, W.N., and B. Tacheba. 2003. Floristic Diversity of the Okavango Delta, Botswana. Pages 69-96 in Alonso, L.E., and L. Nordin, eds. A Rapid Biological Assessment of the Aquatic Ecosystems of the Okavango Delta, Botswana: High Water Survey. RAP Bulletin of Biological Assessment 2. Conservation International. Washington, D.C.

Florida Aquatic. 2008. Aeschynomene fluitans. http://floridaaquatic.com/surface_aeschynomene_fluitans.html. Accessed on 08/28/2017.

Franck, A.R. (curator). 2015. University of South Florida Herbarium (USF). University of South Florida, Tampa, FL. http://www.florida.plantatlas.usf.edu/.

Holland, L. 2017. Personal Communication.

Lewis, G. 2007. Personal Communication.

Pond Megastore Wholesale Waterlilies Department. 2017. Botswana Wonder | Aeschynomene fluitans | Large Sensitive. https://wholesalewaterlilies.com/collections/floating-pond-plants-wholesale-distributor/products/botsawana-wonder-aeschynomene-fluitans. Accessed on 08/28/2017.

Rust, K. 2007. Personal Communication. Absolute Aquatics, Inc.

Strohbach, B. 2013. Vegetation of the Okavango River valley in Kavango West, Namibia. Pages 321-339 in Oldeland, J., C. Erb, M. Finckh, and N. Jürgens, eds. Environmental Assessments in the Okavango Region. Volume 5. Biodiversity & Ecology.

Verdcourt, B. 2000. Papilionideae. Page 175 pp in Pope, G.V, ed. Flora Zambesiaca. Volume 3, Part 6. Royal Botanic Gardens. Kew, Richmond, UK. http://plants.jstor.org/stable/10.5555/al.ap.flora.fz2618.

Other Resources:

Aeschynomene fluitans - Species Page - ISB: Atlas of Florida Plants (photos and vouchers)

Flora of Zimbabwe (photos and record details)

Author: Pfingsten, I.A.

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.