6.  Cyperus echinatus (Linnaeus) A. Wood, Class-book Bot. 734. 1861.  Scirpus echinatus Linnaeus, Sp. Pl. 1: 50. 1753.  Mariscus echinatus (Linnaeus) Elliott, Sketch Bot. S. Carolina  1: 75. 1821.--Type: locality unknown, presumably from eastern U.S.A. (Lectotype designated by Carter and Kral [1990]: LINN 71.35, matched with Carter 3251, photograph VSC!).     Kyllinga ovularis Michaux, Fl. Bor. Amer. 1: 29. 1803.  Mariscus ovularis (Michaux) Vahl, Enum. Pl. 2: 374. 1805.  Cyperus ovularis (Michaux) Torrey, Ann. Lyceum Nat. Hist. New York  3: 278. 1836.--Type: U.S.A. South Carolina: Michaux's garden near Charleston (Lectotype designated by Carter and Kral [1990]: P, matched with Carter 3360 and 3251, photograph VSC!).    Mariscus sphaerocephalus Steudel, Syn. Pl. Glumac. 316. 1855.--Type: Am. sptr., Watson s.n. (Holotype: P).    Mariscus drummondii Steudel, Syn. Pl. Glumac. 316. 1855.--Type: U.S.A. Louisiana:  New Orleans, Drummond 390 (Holotype: P).     Cyperus ovularis var. sphaericus Boeckeler, Linnaea 36: 378. 1870.--Type: U.S.A. Louisiana: Willdenow Herbarium 1428 [Desfontaines s.n.] (Lectotype designated here: B, photograph VSC!).  Note: Boeckeler also cited Drummond 390, which was not found.     Cyperus ovularis var. americanus Boeckeler, Linnaea 36: 377. 1870.--Type: U.S.A. Pennsylvania: America septentr. Willdenow Herbarium 1429 [sheet no. 1, Muhlenberg 395] (Lectotype designated here: B, photograph VSC!).  Note: Willdenow Herbarium 1429 sheet 2 (B, photograph VSC!) is Cyperus retrorsus Chapman and is rejected as a candidate for lectotype in order to conserve the synonymy established by Kükenthal (1936, p. 511).     Cyperus wolfii A. Wood, Bot. Gaz. (Crawfordsville) 1: 38. 1876. Cyperus ovularis var. wolfii (Wood) Kükenthal in Engler, Pflanzenreich 4 (20): 512. 1936.--Type: U.S.A. Illinois: [Union County] Anna, J. Wolf s.n. (Holotype: NY!, Isotype: F!).      Perennial herbs, (12--) 30--80 (--118) cm high, sparingly cespitose to solitary.  Corms, 6--17 mm wide.  Stems trigonous, (1.0--) 2--3.6 mm wide, glabrous.  Leaves sparse, green, mostly at least half as long as stem, flat to broadly V-shaped in cross-section, (2--) 3--9 mm wide, upper surfaces and margins scaberulous at least near tip.  Inflorescence of (2--) 4--11 erect to spreading rays; longest rays (1.7--) 2.5--12.7 cm long; peduncles slender, glabrous.  Spikes subglobose to globose, 9--22×7.5--20 mm, (62--) 91--154 spikelets, tight, 24--56 spikelets per mm rachis.  Spikelets subterete to compressed, lanceolate, acute, (3.2--) 4--7 (-- 9.9) mm long, short-stipitate, stipe 0.2--0.4 mm long, rachilla wing whitish, chartaceous medially with membranous border, tightly clasping achene, covering more than half achene face.  Primary inflorescence bracts spreading to divaricate, mostly leaf-like, (2--) 3--4 (--5) exceeding longest ray.  Primary prophylls truncate with two teeth.  Spikelet prophylls rounded, (1.2--) 1.5--2.3 mm long.  Bracteoles narrowly triangular, lowest rarely setaceous, (0.7--) 1.2- -2.6 (--17) mm long.  Floral scales 2--4 (--7) [1--3 (--5) fertile], keel green, wings with brown to reddish brown undercolor, appressed, (2.7--) 3.2--4.2 mm long, narrowly ovate, obtuse to acute or with excurved mucro to 0.2 mm long, chartaceous, loosely clasping achene, and (6--) 8 raised whitish lateral nerves.  Anthers reddish brown, (0.5--) 0.6--0.8 (--0.9) mm long. Achene brown, oblong to elliptic to narrowly obovoid, (2.43--) 2.5--3.5 (--3.67)× longer than wide, (1.6--) 1.8--2.3×0.5--0.7 (-0.8) mm, abruptly tapering at apex and substipitate base.