Author

Amanda Fandal

Best recognition factors

Perennial taller than 15 cm; many stemmed; spikelets in open, umbel-like clusters, relatively large spikelets; 2 style branches; lustrous achene.

Ecology

A widespread salt marsh perennial of tropical America. Usually in salt marshes and brackish marshes, inland 0-50 m, moist sands, muck or marl.

Family

Cyperaceae

Flowers

Stamens 2–3; styles 2-branched, fimbriate.

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Fruit

Achenes lustrous brown, lenticular-obovoid or obpyriform, 1.5–2 mm, appearing striate, with many fine, vertical lines of isodiametric pits.

Habit and stem features

Plants perennial, densely cespitose, up to 1.5 m tall. Bases deep set in substrate, rhizomes absent.

Inflorescences

Anthelae mostly compound, ascending-branched, longer than broad; scapes wandlike, narrowly linear, many-ribbed, 1.5–2(–3) mm thick, distally round or slightly compressed; proximal-most leafy involucral bract mostly shorter than anthela or equaling it, rarely slightly longer.

Leaves

Leaves erect or ascending, 1/2–2/3 plant height, bases of leaves hard, leathery, usually dark brown or castaneous. Sheaths distally bristly-ciliate, backs chestnut brown, glabrous; ligule absent or incomplete. Blades narrowly linear, 1–2(–3) mm wide or thick, mostly strongly involute or adaxially deeply sulcate. Margins ciliate-scabrous, surfaces glabrous.

References

Flora North America. (2004). Accessed November 25, 2006 from the World Wide Web at http://www.fna.org/FNA/.                                                                                                                  

Godfrey, Robert K. and Wooten, Jean W. 1979. Aquatic and Wetland Plants of the Southeastern United States: Monocotyledons. Athens, Georgia: The University of Georgia Press.

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Species name

Fimbristylis castanea (Michaux) Vahl

Spikelets

Chestnut brown to dull brown, ellipsoid, ovoid, or cylindric, 5–20 mm; fertile scales broadly ovate to nearly orbiculate, 3.5–4.5 mm, apex rounded, sometimes ciliolate, midrib reaching tip or excurrent as short mucro.

Synonyms

Scirpus castaneus Michx.; Fimbristylis cylindrica Vahl; F. spadicea (Linnaeus) Vahl var. castanea (Michaux) A. Gray