264 < CYPERACEAE. 
7. Scirpus Hallii A. Gray. Hall’s Club-rush. (Fig. 615.) 
Scirpus Hallit A. Gray, Man. Ed. 2, Add. 1863. 
sh es supinus var. Hallii A. Gray, Man. Ed. 5, 563. 
ip 
Annual, culms very slender, smooth, tufted, ob- 
tusely 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/-214’ 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 ex- 
current tip of the midvein; bristles wanting; 
stamens mostly 2; achene obovate-orbicular or 
slightly broader than high, black, plano-convex, 
mucronulate strongly wrinkled transversely, about 
44’ in diameter. 
In wet soil, Massachusetts to Florida, west to Illinois, Colorado, Texas and Mexico. The lowest 
sheaths occasionally subtend a flower with very long styles. July—Sept. 
8. Scirpus débilis Pursh. Weak-stalked Club-rush. (Fig. 616.) 
Scirpus debilis Pursh, Fl. Am. Sept. 55. 1814. 
Annual, smooth, culms slender, terete or nearly 
so, 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, ovyoid-oblong, subacute, many-flowered, 
appearing lateral, the solitary involucral leaf nar- 
rowly linear, 11%4’-4’ long, erect or divergent; 
scales light yellowish-brown with a green midyein, 
broadly ovate, obtuse or acute; bristles 4-6, 
downwardly barbed, somewhat unequal and about 
as long as the achene; stamens 2-3; style 2-cleft or 
rarely 3-cleft; achene plano-convex, broadly ob- 
ovate or orbicular, smooth or slightly roughened, 
dark brown, shining, obtuse, mucronulate. 
In wet soil, Maine to Minnesota, south to Georgia, 
Alabama and Nebraska. July—Sept. 
g. Scirpus Smithii A. Gray. Smith’s 
Club-rush. (Fig. 617.) 
Scirpus Smithii A. Gray, Man. Ed. 5, 563. 1867. 
Annual, similar to the preceding species, but the 
culms usually lower and more slender or nearly fili- 
form, 3/—12/ tall, the sheaths oblique and acumi- 
nate or the upper one bearing a subulate blade. 
Spikelets 1-4, in an apparently lateral cluster, 
ovoid, acute, 2’’-3’’ long, the involucral leaf very 
narrow, elongated, erect; scales oblong, obtuse, 
mucronulate, pale brown with a narrow, green mid- 
vein; bristles usually wanting, sometimes I-3, and 
very much shorter than the achene; style 2-cleft; 
achene plano-convex, obovate or orbicular, brown, 
rather dull, smooth or minutely roughened, obtuse, 
mucronulate. 
In wet muddy places, Vermont to Minnesota, south 
to Delaware, Pennsylvania and Michigan. Perhaps 
only a form of the preceding. July—Sept. 
