156 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Rance: Washington to New Brunswick, south to California and Florida. 
SPECIMENS EXAMINED: West Klickitat County, Suksdorf 223; Almota, Piper 2651. 
ZONAL DISTRIBUTION: Upper Sonoran. 
DULICHIUM. 
1. Dulichium arundinaceum (L.) Britton, Bull. Torr. Club 21: 29. 1894. 
Cyperus arundinaceus L. Sp. Pl. 1: 44. 1758. 
Schoenus spathaceus L. Sp. Pl. ed. 2. 1: 63. 1762. 
Cyperus spathaceus L. Syst. ed. 12. 2: 735. 1767. 
Dulichium spathaceum Pers. Syn. 1:65. 1805. 
Type Locauity: “ Habitat in Virginia.” 
Rance: British Columbia to Nova Scotia, south to Oregon, Texas, and Florida. 
SPECIMENS EXAMINED: Seattle, Piper 692; Lakeview, Flett, September 20, 1899. 
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ZONAL DISTRIBUTION: Humid Transition. 
SCIRPUS. 
Spikelets solitary, terminal. 
Involucral bract present, not longer than the spikelet. 
Perianth bristles none ......-.-....--.-.-.-.--+2--0--- 1. S. riparius. 
Perianth bristles 6, smooth. ...............-.-.--------- 2. S. cespitosus. 
Involucral bract 2 to 3 times as long as the spikelet ........... 3. 8. subterminalis. 
Involucral bract wanting -......2...2.2.2.2.2.2.-.-.---2--- 4. S. pauciflorus. 
Spikelets several to many, rarely solitary. 
Stems terete. 
Inflorescence apparently lateral, sessile .........-...-.--- 5. S. nevadensis. 
Inflorescence umbellate. 
Akenes 2 mm. long, the scales little longer. .........- - 6. 8, validus. 
Akenes 2.5 to 3 mm. long, the scales one-fourth longer. 7. S. occidentalis. 
Stems three-angled. 
Involucral leaf solitary 2... 2.2.2.2.202.-.-.-.--------- 8. S. americanus, 
Involucral leaves several. 
Spikelets 1 to 2 em. long. 
Akenes oblong-obovate, pale...........-.....--- 9. S. brittonianus. 
Akenes orbicular-obovate, dark .............2.-- 10. S. robustus. 
Spikelets 3 to 5 mm. long. 
Akenes 3-angled; bristles 6 .....2..22.222-.-.--- 11. S. atrovirens. 
Akenes plano-convex; bristles 4................. 12. 8. microcarpus. 
1. Scirpus riparius (R. Br.) Spreng. Syst. 1: 208. 1825. 
Isolepis riparia R. Br. Prod. Fl. Nov. Hol. 222. 1810. 
TyPE Locauity: Port Jackson, Australia. 
Rance: Washington to California. South America. Australia. Africa. 
SPECIMENS EXAMINED: Whidby Island, Gardner 318; Seattle, Piper 2860. 
ZONAL DISTRIBUTION: Humid Transition. 
2. Scirpus cespitosus L. Sp. Pl. 1: 48. 1753. 
Type LocALITy: Europe. 
Rance: Alaska to Greenland, south to Washington, Colorado, and New York. 
SPECIMENS EXAMINED: Olympic Mountains, Piper 2248; Skamania County, Suksdorf 
2241; Cascade Mountains, 49°, Lyall in 1860; Stevens Pass, Sandberg & Leiberg775; Bridge 
Creek, Elmer 644; Granville, Conard 376. 
ZONAL DISTRIBUTION: Arctic. 
