7. Scirpus Hallii A. Gray. Hall's Club-Rush

Fig. 807

Scirpus Hallii A. Gray, Man. Ed. 2, Add. 1863.

S. supinus var. Hallii A. Gray, Man. Ed. 5, 563. 1867.

Annual, culms very slender, smooth, tufted, obtusely triangular, erect, striate, 5'-12' tall. Lower sheaths oblique, and acuminate or mucronate on one side, the upper one commonly bearing a filiform blade, 4'-2 1/2' long; spikelets capitate in clusters of 1-7, oblong-cylindric, obtuse, many-flowered, 3"-6" long, about 1" thick, appearing lateral by the extension of the solitary involucral leaf which is 1'-4' long; scales ovate-lanceolate, light greenish brown, acuminate, keeled, cuspidate by the excurrent tip of the midvein; bristles wanting; stamens mostly 2; achene obovate-orbicular or slightly broader than high, black, planoconvex, mucronulate, strongly wrinkled transversely, about 1/2" in diameter.

In wet soil, Massachusetts to Florida, west to Illinois, Colorado, Texas and Mexico. Also in eastern Asia. The lowest sheaths occasionally subtend a flower with very long styles. July-Sept.

7 Scirpus Hallii A Gray Hall s Club Rush 807

8. Scirpus Debilis Pursh. Weak-Stalked Club-Rush

Fig. 808

Scirpus debilis Pursh, Fl. Am. Sept. 55. 1814. Scirpus Smithii A. Gray, Man. Ed. 5, 503. 1867.

Annual, smooth, culms slender, obtusely triangular or nearly terete, tufted, erect or ascending, 6'-2° high. Sheaths obliquely truncate, the upper one rarely bearing a short subulate blade; spikelets capitate in clusters of 1-12, ovoid-oblong, subacute, many-flowered, appearing lateral, the solitary involucral leaf narrowly linear, 1 1/2-4' long, erect or divergent; scales light yellowish-brown with a green midvein, broadly ovate, obtuse or acute; bristles 4-6, downwardly barbed, somewhat unequal and about as long as the achene or short or wanting; stamens 2-3; style 2-cleft or rarely 3-cleft; achene plano-convex, broadly obovate or orbicular, smooth or slightly roughened, dark brown, shining, obtuse, mucronulate.

In wet soil. Maine to Ontario, Minnesota, Georgia, Alabama and Nebraska. July-Sept.

8 Scirpus Debilis Pursh Weak Stalked Club Rush 808

9. Scirpus Americanus Pers. Three-Square. Chair-Maker's Rush. Sword-Grass

Fig. 809

Scirpus americanus Pers. Syn. 1: 68. 1805. Scirpus puugens Vahl, Enum. 2: 255. 1806. Scirpus americanus longispicatns Britton, Trans. N. Y.

Acad. Sci. 11: 78. 1892. S. Olneyi contortus Eames, Rhodora 2: 220. 1907.

Perennial by long rootstocks, culms sharply triangular with concave sides or one of the sides nearly flat, erect, stiff, 1°-4° tall. Leaves 1-3, narrowly linear, keeled, shorter than the culm; spikelets oblong-ovoid, acute, 4"-12" long, capitate in clusters of 1-7, appearing as if lateral; involucral leaf solitary, slender, 1 1/2-4' long; scales broadly ovate, brown, often emarginate or sharply 2-cleft at the apex, the midvein extended into a subulate awn sometimes 1" long, the margins scarious, ciliolate or glabrous; bristles 2-6, downwardly barbed, shorter than or equalling the achene; stamens 3; style usually 2-cleft; achene obovate, plano-convex, smooth, dark brown, mucronate.

In fresh water and brackish swamps, temperate North America, north to Newfoundland. Also in South America and Europe. June-Sept.

9 Scirpus Americanus Pers Three Square Chair Maker 809