Flora of the Southeastern United States

*Imperata cylindrica (Linnaeus) Palisot de Beauvois. Common name: Cogongrass. Phenology: Feb-May (-Nov). Habitat: Pinelands, grassy roadsides, pastures. An extremely aggressive and dangerous weed, now well-established and rapidly invading fire-maintained Coastal Plain areas (such as longleaf pine and slash pine flatwoods and longleaf pine clayhills) on the Gulf Coastal Plain of FL, AL, and MS. Distribution: Native of se. Asia, s. Asia, and possibly e. Africa. See Nelson (1993) for first report from SC.

ID notes: Imperata cylindrica has long yellow-green leaves with an obviously off-center midrib and slightly serrated margins. These leaves are roughly 1-2 cm wide and can grow to over 1.5 m tall. This height means that cogongrass often stands out from surrounding vegetation, making it easy to spot from a distance. The panicle is silvery white in color, fuzzy like cotton, cylindrical in shape, and is usually no longer than 8” in length. The stem is typically hidden by the leaves but can be easily observed in smaller specimens.

Origin/Endemic status: Paleotropics

Taxonomy Comments: Hall (1998) argues that I. cylindrica and I. brasiliensis are not distinct. Ward (2004c) treats the 2 taxa at varietal level.

Synonymy ⓘ: = FNA25, HC, K4; = Imperata cylindrica (L.) P.Beauv. var. cylindrica — Ward (2004c); = n/a — C, RAB, S, S13, Tat; < Imperata cylindrica (L.) P.Beauv. — FlGr, Hall (1998); Lagurus cylindricus Linnaeus. Basionym: Lagurus cylindricus L. 1759

Links to other floras: = Imperata cylindrica - FNA25

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Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: UPL (taxonomic split from wetland indicator species)
• Eastern Mountains and Piedmont: FACU
• Great Plains: FACU (taxonomic split from wetland indicator species)

Heliophily ⓘ: 7