Schoenoplectus pungens (Vahl) Palla var. pungens . Common Threesquare, Chairmaker's Rush, Swordgrass. Phen: Mid May-Jun; Jun-Sep. Hab: Tidal marshes, other marshes, inland salt marshes, rocky river beds, wet meadows, lake edges, moist fields. Dist: The species is circumboreal, ranging in North America from NL (Newfoundland) west to AK, south to South America; var. pungens is widespread.

ID notes:The leafless stems of Schoenoplectus pungens var. pungens are triangular in cross-section and grow 2-6 feet tall. The tallest plants are maritime; the shortest grow inland in rivers. Near the summit of each stem is a single compact cluster of spikelets, with an erect bract that looks as if it were a continuation of the stem. This species is very much like Schoenoplectus americanus, but Schoenoplectus pungens var. pungens's color is dull green (vs. bright green), stems are merely triangular (vs. sharply so and with concave sides in Olney's Threesquare), and the inflorescence bracts are longer (3-20 cm long vs. 1-6 cm long in that species).

Origin/Endemic status: Native

Taxonomy Comments: This taxon traditionally had the name Scirpus americanus applied to it; this name, however, is properly applied to the traditional Scirpus olneyi. Schoenoplectus pungens (or Scirpus pungens) becomes the correct name for this plant (Schuyler 1974).

Synonymy: = FNA23, K1, K3, K4, Mo1, NE, NY, Va, Smith (1995); = Scirpus pungens Vahl var. pungens – C; < Schoenoplectus pungens (Vahl) Palla – Ar, Il, Mi, NcTx, Tn, WH3, Strong (1994); < Scirpus americanus Pers. – F, G, GW1, RAB, S, S13, Tat, W, WV, misapplied; < Scirpus pungens Vahl – GrPl, Pa

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Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: OBL (taxonomic split from wetland indicator species)
• Eastern Mountains and Piedmont: OBL (taxonomic split from wetland indicator species)
• Great Plains: OBL (taxonomic split from wetland indicator species)
• Midwest: OBL (taxonomic split from wetland indicator species)
• Northcentral & Northeast: OBL (taxonomic split from wetland indicator species)

Heliophily: 9