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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Cuban bulrush

Synonyms and Other Names: Oxycaryum cubense

Identification: Cuban bulrush is a floating, epiphytic perennial herb (sedge), with a slender, erect triangular stem that is 30 to 92 cm in height. Slender leaves form at the base of the stem and extend above the water surface (Godfrey 1979). The reddish runners form mass together or with the roots/rhizomes of other plants to form floating mats (tussocks; Mallison et al. 2001, Bryson 2008).

Multiple inflorescences, either umbellate (short flower stalks which spread from a common point) or monocephalous (a single flower head which is unbranched) depending on form, are produced at the apical portion of each stem. Inflorescences are comprised of one to thirteen spherical heads that are 1-2 cm in diameter. The inflorescence is surrounded by 2 to 6 long leaf-like bracts. Seeds are in the form of spiked, buoyant ale or red-brown achenes (small, dry one-seeded fruit), which form in the spring through fall (Godfrey 1979, Bryson 2008).

Size: Stems can range from 30 to 92 cm in height (Godfrey 1979).

Native Range: Cuban bulrush is native to South America and the West Indies.

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

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

Ecology: Cuban bulrush is found in free-floating mats and rafts that vary greatly in size.  This species commonly establishes in freshwater ditches, marshes, ponds, lakes, rivers, and swamps (Bryson 2008). It is unclear if this species requires other vegetation for establishment and mat formation, but it appears that the epiphytic form of Cuban bulrush prefers areas of dense floating aquatic vegetation.

Means of Introduction: Cuban bulrush was likely introduced via ship ballasts and by achenes ingested and transported by migratory birds (Bryson 2008). Once in drainage, Cuban bulrush floating islands (or tussocks; Mallison et al. 2001) or seeds (Markwith et al. 2014) can disperse the plant downstream.

Status: Cuban bulrush is widespread throughout tropical and subtropical areas of Africa and the Americas, but is currently established in only six states in the southeastern United States (Bryson 2008).

Impact of Introduction:

Summary of species impacts derived from literature review. Click on an icon to find out more...

Ecological	Economic

Cuban bulrush is known to form large floating islands (tussocks) that have numerous economic and ecological impacts on the waterbody. The tussocks have been observed blocking boat launches and impede navigation and recreation within waterbodies (Mallison et al. 2001, Bryson et al. 2008) and accumulating along shorelines (Mallison et al. 2001). The tussocks can also exclude and shades out desirable submersed vegetation ( Mallison et al. 2001, Robles et al. 2007, Bryson et al. 1996, 2008). Cuban bulrush is thought to be able to compete with other emergent plants (water hyacinth, water lettuce, and mosquito ferns) due to its tall epiphytic growth habit (Tur 1971, Robles et al. 2007). Underneath the floating mats, water quality can rapidly degrade due to increased organic matter and low dissolved oxygen (Mallison et al. 2001).

Remarks: To date, little is known regarding basic biological and ecological characteristics of this plant.  Additionally, there have not been any management recommendations developed for this species. Cuban bulrush is expanding in the MidSouth region of the United States and additional research is needed to develop techniques to slow its spread.

References: (click for full references)

Bryson, C.T., V.L. Maddox, and R. Carter. 2008.  Spread of Cuban club-rush (Oxycaryum cubense) in the Southeastern United States.  Invasive Plant Science and Management 1:326-329.

Godfrey, R.K. and J.W. Wooten. 1979.  Aquatic and Wetland Plants of Southeastern United States: Monocotyledons.  Athens, GA: University of Georgia Press. 348 p.

Mallison, C.T., R. K. Stocker, and C. E. Cichra.  2001. Physical and vegetative characteristics of floating islands.  Journal of Aquatic Plant Management.  39:107-111.

Markwith, S.H., Mezza, G., Kennard, S.N. and S.G. Bousquin. 2014. Intra-Floodplain seed dispersal limitation and wetland community restoration. Ecological Restoration 32(3):249-259.

Robles, W., Madsen, J.D., Maddox, V.L. and R.M. Wersal. 2007. The invasive status of giant salvinia and hydrilla in Mississippi. Proceedings of the 37th Annual Mississippi Water Resources Conference:109-113.

Author: McLaurin, C.S., Wersal, R.M., and Daniel, W.M.

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.