Scirpus microcarpus J. Presl & C. Presl

Scirpus microcarpus Presl, Rel. Haenk. 1: 195. 1828
Scirpus lenticularis Torr. Ann. Lye. N. Y. 3: 328. 1836.
Scirpus sylvaticus /3 digynus Bock. Linnaea 36: 727. 1870.
Scirpus sylvaticus var. microcarpus MacM. Metasp. Minn. Valley 97. 1892.
Scirpus Macounii Holm, Am. Jour. Sci. IV. 18: 21. 1904.
Scirpus microcarpus var. longispicatus M. E. Peck, Proc. Biol. Soc. Wash. 47: 185. 1934.
Stout perennial 0.5-1.3 m. tall, erect from thick rhizomes; leaves up to 1 m. long, often exceeding the culm, the sheaths mostly green but often tinged with red, the blades 0.5-2.5 cm. broad, green, often nodulose, strongly scabrous on the margins and midrib; involucral bracts 3-many, to 1.5 cm. broad, leaflike, variable in length, equaling but not exceeding the mature inflorescence; inflorescence spreading, compound-umbellate, the primary rays to 2 dm. long, terete or angled, obscurely scabrous, the secondary branches usually ca. 5 cm. long, the tertiary shorter and capped by 3-8 spikelets; spikelets greenish-black, mostly 3-5 mm. long, 2 mm. broad, lanceolate-acute; style bifid, brick-red; bristles 4-6, whitish, fragile, obscurely scabrous, exceeding the achene; achene 1.25-1.5 mm. long, white, lenticular, apiculate.
Type locality: "In Nootka-Sund."
Distribution : Moist shady banks ; Alaska, south to New Mexico and California.

Scirpus rubrotinctus Fernald, Rhodora 2: 20. 1900
Scirpus microcarpus var. robrotinctus M. E. Jones, Bull. Univ. Mont. Biol. 15: 20. 1910.
Scirpus rubrotinctus var. conferttis Fernald, Rhodora 2:21. 1900.
Scirpus avatshensis Kom. Repert. Sp. Nov. 13: 163. 1914.
Scirpus microcarpus var. conferlus House, Bull. N. Y. State Mus. 233-234: 62. 1921.
Scirpus rubrotinctus f. conferlus Weath. Bull. Conn. Geol. Nat. Hist. Surv. 48: 29. 1931.
Scirpus rubrotinctus f. radiosus Fernald, Rhodora 45: 295. 1943.
Perennial from stout, reddish stolons; roots fibrous; culm rather stout, 4-9 dm. high, 0.5-1.5 cm. thick at the base, green, triangular, smooth; leaves to 12 mm. broad, the upper equaling or slightly exceeding the inflorescence, the sheaths mostly red-tinged at the base, the blades scabrous on the margins only, tapered to a rounded tip; involucral leaves mostly 3, the longest equaling or exceeding the inflorescence, strongly scabrous on the margins; rays numerous, the 3-5 longest 0.5-1.5 dm. long, stiff, ascending, subequal, the many shorter ascending and divergent; spikelets 4-9 mm. long, ovoid to cylindric, iu glomerules of 3-many; scales 1.5-2 mm. long, ovate, blunt or somewhat mucronate, the weak midrib green or white, the margins greenish-black; bristles 6, whitish, stiff, retrorsely scabrous, equaling or slightly exceeding the achene; style bifid, reddish; achene 0.75-1 mm. long, white, oval, lenticular, slightly apiculate.
Type locality: Foxcroft, Maine.
Distribution: Damp soil; Newfoundland, south to New Jersey and west through the Great Lakes to Colorado, Idaho, and British Columbia.