http://nas.er.usgs.gov/taxgroup/plants/docs/utric_in.html

Utricularia inflata Walter

Common Name: swollen bladderwort, floating bladderwort

Taxonomy: Family-; Order-Scrophulariales; Subclass-Asteridae; Class-Magnoliopsida (Dicots); Division-Magnoliophyta (Angiosperms).

Identification: Submersed free-floating characterised by small bladders attached to stems that branch in a leaflike fashion. Yellow flowers are carried on tall stalks (scapes) held above the water by a of inflated branches, resembling spokes of a wheel (Burks 1996; Rossbach 1939). species are carnivorous in that the bladders trap and digest tiny animals, especially small crustaceans (Godfrey and Wooten 1981). Uticularia inflata is oftentimes confused with, yet morphologically distinct from, the smaller and more widespread U. radiata Small (U. inflata var. minor Chapman) (Reinert and Godfrey 1962).

Native Range: The Atlantic and Gulf coastal plains, extending from southern to and westward to eastern and southeastern (Godfrey and Wooten 1981; Nelson and Couch 1985). New discoveries in southeastern (Miller and Mitchell 1995) and in eastern (Sorrie 1992) add to its northern range. While the New York station is regarded as an extension of range, introduction, either by man or waterfowl is considered a possible reason for its disjunct appearance in Massachusetts. in Massachusetts are reported as especially large, with scapes reaching up to 23 cm (Sorrie 1992).

Habitat: Quiet waters of lakes, ponds, marshes and swamp forests.

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Nonindigenous Occurrences: Initially detected from the western in 1980 from Horshoe Lake, Kitsap County, in the region of (Ceska and Ceska 1986). Subsequently reported in increasing numbers from lakes within the area, where flowering is observed (Parsons 1996; K. Hamel pers. comm. 1998).

Means of Introduction: Located far from its natural range, there is little chance that Utricularia inflata was carried to western Washington by migrating waterfowl. More than likely it was liberated intentionally, either as an ornamental or by someone anticipating mosquito control. Waterfowl are suspected to be spreading the plant from lake to lake within the local region (K. Hamel pers. comm. 1998). Plants reproduce vegetatively and by seed.

Status: At a pioneering stage in western Washington where reports are increasing and its proliferation is considered a nuisance (WSDE 1998).

Remarks: Floating U. inflata is known to grow abundantly in its native range, especially in shallow waters, following drought or drawdown. Its competativeness in the southern US is diminished by the fact that it's major growth period occurs in the late winter-early spring, and it is inactive during the the major summer growing season (Sanders and Mangrum 1973). This aspect could make Utricularia inflata more competative in the relatively cooler growing season of the Pacific Northwest.

References:

Burks, K.C. 1996. Spin-the-Wheel Bladderworts. Aquaphyte(16)2:12.

Ceska, A. and O. Ceska. 1986. Noteworthy collections - Washington. Utricularia inflata Walt. (Lenticulariaceae). Madrono 33(1):80.

Godfrey, R.K. and J.W. Wooten. 1981. Aquatic and Wetland Plants of the Southeastern United States: Dicotyledons. The University of Press, Athens, GA.

Hamel, K. Washington Department of Ecology, Olympia, WA. Personal communication to C. Jacono, June 1998.

Miller, N.G. and R.S. Mitchell. 1995. Tracking the mosses and vascular plants of New York (1836-1994). In: Our Living Resources: A Report to the Nation on the Distribution, Abundance,

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and Health of U.S. Plants, Animals, and Ecosystems, E.T. Laroe, C.E. Farris, et al. (eds.) U.S. Dept. Interior, National Biological Service, Washington, DC.

Nelson, E.N. and R.W. Couch. 1985. Aquatic Plants of Oklahoma I: Submersed, Floating-leaved, and Selected Emergent Macrophytes. Oral Roberts Unversity, Tulsa, OK.

Parsons, J.P. 1996. Technical Assistance Program: 1995 Activity Report. Washington State Department of Ecology, Environmental Investigations and Laboratory Services Program, Olympia, WA.

Reinert, G.W. and R.K. Godfrey. 1962. Reappraisal of Utricularia inflata and U. radiata (Lentibulariaceae). American Journal of Botany 49(3):213-220.

Rossbach, G.B. 1939. Aquatic Utricularias. Rhodora 41(484):113-127.

Sanders, D.R. and M.O. Mangrum. 1973. Competition between Cabomba and Anacharis in Black Lake, . Proc. Southern Weed Science Society 26:361-66.

Sorrie, B.A. 1992. Utricularia inflata Walter (Lentibulariaceae) in Massachusetts. Rhodora 94(880):391-392.

Washington State Department of Ecology, Water Quality Program. 1998. Aquatic Plants and Lakes Issues. http://www.wa.gov/ecology/wq/plants/bladder.html

Author: Colette Jacono

Revision Date: 6 July 1998

This page was prepared by the Center for Aquatic Resource Studies. The Center is part of the Biological Resources Division of the Geological Survey within the U. S. Department of the Interior

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