SEDGE FAMILY. 243 
22. Cyperus Engelm4nni Steud. Engelmann’s Cyperus. (Fig. 564.) 
———— 
Cyperus Engelmanni Steud. Syn. Pl. Cyp. 47. 1855. } 
Annual, culms slender, 6/-2%° tall. Leaves 
elongated, 2’’-3’’ wide, flaccid, roughish on the 
margins, those of the involucre 4-6, the longer 
exceeding the umbel; umbel often compound, the 
raylets very short; spikelets often densely crowded, 
very narrowly linear, subterete, 6’/-12’’ long, 
5-15-flowered ; rachis narrowly winged; scales 
greenish-brown, oblong, obtuse, thin, faintly 3-5- 
nerved on the back, distant, the successive ones 
on each side of the spikelet separated by a space 
of about one-half their length; stamens 3; style 
3-cleft; achene linear-oblong, 3-angled, two-thirds 
as long as the scale. 
In wet soil, Massachusetts to southern Ontario and 
Wisconsin, south to New Jersey and Missouri. Aug.— 
Oct. 
23. Cyperus strigdsus L. Straw-colored Cyperus. (Fig. 565.) 
Cyperus strigosus Y,. Sp. Pl. 47. 1753- 
Perennial by basal tuber-like corms, culm 
rather stout, 1°-3° tall. Leaves somewhat 
rough-margined, 2//’-3/’ wide, the longer 
ones of the involucre much exceeding the 
umbel; umbel several-rayed, compound or 
nearly simple, some of the primary rays 
often 4/-6/ long, their sheaths terminating in 
2 bristles; involucels setaceous; heads ob- 
long or ovoid; spikelets flat, linear, 4’/-9’’ 
long, 1// wide or less, 7—15-flowered, sepa- 
rating from the axis at maturity; scales 
straw-colored, oblong-lanceolate, subacute, 
strongly several-nerved, appressed or at 
length somewhat spreading; stamens 3; 
style 3-cleft; achene linear-oblong, 3-angled, 
acute, about one-third as long as the scale. 
In moist meadows, swamps or along streams, 
Maine and Ontario to Minnesota, south to Flor- 
ida and Texas. Aug.—Oct. 
Among the numerous forms of this species 
the following may be defined as varieties: 
Cyperus strigosus capitatus Boeckl. Linnaea, 36: 347. 1869-70. 
Umbel simple or nearly so; spikelets 4''~7'’ long, densely capitate in subglobose heads. Range 
of the type. 
Cyperus strigosus compositus Britton, Bull. Torr. Club, 13: 212. 1886. 
Umbel very compound; heads cylindric; spikelets 3'’-6'' long, 4-6-flowered. Southern New 
York and Pennsylvania to Alabama. 
Cyperus strigésus robustior Kunth, Enum. 2:88. 1837. 
Umbel compound; spikelets 8'’-12'’ long, 10-25-flowered. Range of the type. 
