13. Cyperus Bushii Britton. Bush's Cyperus

Fig. 733

Cyperus Bushii Britton, Man. 1044. 1901.

Perennial by tuber-like corms. Leaves 1 1/2"-2" wide, smooth; culms smooth, 1°-2° high, longer than the leaves; longer involucral bracts much exceeding the umbel; umbel capitate, or with 1-5 rays; spikelets loosely capitate, flat, linear, acute, 4"-8" long; scales firm, shining, oblong, mucronate, strongly about 11-nerved falling away from the persistent axis of the spikelet at maturity; achenes oblong, 3-angled, nearly twice as long as thick, apicu-late, two-thirds as long as the scale, sometimes persistent after the scales fall.

Sandy soil, Minnesota to Idaho, Missouri, Texas and Colorado. Resembling C. filiculmis, but the axis of the spikelet is persistent after the scales fall away. July-Sept.

14. Cyperus Pseudovegetus Steud. Marsh Cyperus

Fig. 734

Cyperus pseudovegetus Steud. Syn. PI. Cyp. 24. 1855. Cyperus calcaratus Nees; S. Wats, in A. Gray, Man. Ed. 6, 570. 1890.

Perennial by thickened tuber-like joints of the root-stocks, culm rather stout, 1°-4° high, often equalled by the leaves. Leaves 1 1/2"-2" wide, smooth, nodulose, the midvein prominent; leaves of the involucre 4-6, spreading, the longer much exceeding the inflorescence; umbel several-rayed, compound, the primary rays often 4' long; spikelets ovate, flat, many-flowered, light green, densely capitate, 2"-3" long; scales keeled, condupli-cate, i-nerved, curved, acute, longer than the linear 3-angled slightly stalked achene; stamen 1; style 3-cleft.

In marshes, New Jersey to Florida, Kentucky, Missouri, Kansas and Texas. Also in the Bahamas. July-Sept.

15- Cyperus Acuminatus Torr. & Hook. Short-Pointed Cyperus

Fig. 735

Cyperus acuminatus Torr. & Hook. Ann. Lye. N. Y. 3: 435. 1836.

Annual, culms very slender, tufted, 3'-15' tall, longer than or equalling the leaves. Leaves light green, usually less than 1" wide, those of the involucre much elongated; umbel 1-4-rayed, simple; rays short; spikelets flat, ovate-oblong, obtuse, 2"-4" long, many-flowered, densely capitate; scales oblong, pale green, 3-nerved, coarsely cellular, conduplicate, with a short sharp more or less recurved tip; stamen 1; style 3-cleft; achene sharply 3-angled, gray, oblong, narrowed at each end, about one-half as long as the scale.

In moist soil, Illinois to South Dakota, Louisiana, Iowa, Kansas, Texas, Oregon and California. July-Oct.

16. Cyperus Fuscus L. Brown Cyperus

Fig. 736

Cyperus fuscus L. Sp. PI. 46. 1753.

Annual, culms slender, tufted, 6-15' high, longer than or equalled by the leaves. Leaves rather dark green, about 1" wide, those of the involucre 4-6, the longer much exceeding the inflorescence; umbel several-rayed, somewhat compound, the rays short; spikelets linear, 2"-7" long, less than 1" wide, many-flowered, acute; scales ovate, subacute, becoming dark brown or remaining greenish on the keel, faintly about 3-nerved on the back, separating from the narrowly winged rachis as they mature; stamens 2 or 3; style 3-cleft; achene sharply 3-angled, oblong, pointed at each end, nearly as long as the scale.

Waste grounds and in ballast, eastern Massachusetts to New Jersey and Maryland. Adventive from Europe. July-Sept.