60.
Cyperus
houghtonii
Torrey, Ann. Lyceum Nat. Hist. New York. 3: 277. 1836.
Houghton's flatsedge
Herbs, perennial, cespitose, bases cormose, rhizomatous. Culms trigonous, 5—50 cm × 0.5—1.5 mm, glabrous. Leaves V-shaped, 12—30 cm × 1—6 mm. Inflorescences: spikes ± globose to broadly ovoid, 8—20 mm wide; rays 1—8 cm; rachis 2—5 mm, glabrous; bracts 3—8, weakly ascending, flat, 3—20 cm × 1—3.5 mm; rachilla deciduous, wingless. Spikelets 3—18, compressed, ovoid to oblong-lanceoloid, 4—15 × 2.6—3.4 mm; floral scales deciduous, 3—18, laterally stramineous to reddish brown, laterally 3—4-ribbed, broadly ovate, 1.8—2.5 × 1.3—1.6 mm, apex with mucro 0.1—0.2 mm. Flowers: anthers 0.5—0.7 mm; styles 0.4—0.6 mm; stigmas 1—1.5 mm. Achenes dark brown, sessile, broadly ellipsoid, 1.5—2 × 1—1.5 mm, apex obtuse, apiculate, surface glabrous, puncticulate, or papillose. 2n = 168, 170, 172.
Fruiting summer. Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods, especially among Jack pines; 0—1100 m; Man., Ont., Que.; Ill., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., Ohio, Pa., Vt., Va., W.Va., Wis.
