Checklist » Cyperaceae » Schoenoplectus americanus
Last updated 5/19/2021 by Kevin Armitano.
Schoenoplectus americanus (Pers.) Volkart ex Schinz & R. Keller[FNA23, HC2]
Olney's three-square bulrush

Publication: Fl. Schweiz ed. 2. 1: 75. 1905.

Origin: Native

selected vouchers: WTU

Notes: FNA23: "The secondary involucral bracts of Schoenoplectus americanus lack blades and closely resemble floral scales, in contrast to S. pungens and S. deltarum. Although mostly very locally distributed, S. americanus is ecologically important in many coastal marshes. In recent years it has seriously declined (e.g., in Maryland and Louisiana). It may occur in southwestern Kansas; I have not seen a specimen. It probably has been extirpated from the Missouri station, based on one collection from 1886 (G. Yatskievych, pers. comm.). The report from New Hampshire is based on M. L. Fernald (1950). The stations on the Maine and Connecticut coasts, at Lake Champlain in Vermont, and in Oklahoma are based on putative S. americanus × S. pungens specimens. Some plants in the southwest are atypical in having nearly flat culm sides and leaf blades to 1.5 times as long as their sheaths as in the type of Scirpus monophyllus J. Presl & C. Presl from Peru. The name Scirpes americanus was long misapplied to Schoenoplectus pungens; Schoenoplectus americanus was known as Scirpus olneyi (A. E. Schuyler 1974)."

References: (none)

Synonyms & Misapplied Names:
Scirpus americanus Pers.[HC]
Scirpus olneyi A. Gray[HC]