PIPER—FLORA OF THE STATE OF WASHINGTON. 85 
Stems annual; spikes not mucronate. 
Fertile stems pale-brown, short-lived; sterile with many branches. 
Stems slender, 6 to 10-furrowed...............-.-.---.----.! 5. BE. arvense. 
Stems stout, 20 to 40-furrowed..............--------------- 6. EF. telmateia. 
Fertile stems green like the sterile, naked or branched. 
Stems obscurely ridged; sheaths appressed. ...............-. 7.£. fluviatile. 
Stems acutely ridged; sheaths loose... 2... 2.2..22222-..-- 8. FE. palustre. 
1. Equisetum hyemale L. Sp. Pl. 2: 1062. 1753. SCOURING RUSH. 
Type Locauity: “Habitat in Europae sylvis, asperis, uliginosis.”’ 
\ Range: British Columbia to New England, south to California and Georgia. Europe. 
Asia. 
SPECIMENS EXAMINED: West Klickitat County, Suksdorf 1248, 2161, 2162; Wenache, 
Whited, May 17, 1896; Waitsburg, Horner, February 1, 1897; Pullman, Elmer 294, July 2, 
1896; Port Discovery, Wilkes Expedition. 
ZONAL DISTRIBUTION: Transition to Canadian. 
Mr. A. A. Eaton considers that this variable species consists of several definable sub- 
species. Ours are thus classified: 
Ridges with 2 rows of tubercles... ..-.-.....-.-2-.- hyemale californicum Milde. 
Ridges with bands of silex. 
Sheaths loose; stems stout... .........2.-2.-.-.- hyemale intermedium A. A. Eaton. 
Sheaths close; stems with fertile branches... ._.. - hyemale suksdorfii A. A. Eaton. 
The first subspecies has commonly been referred to £. robustum A. Br. 
2. Equisetum laevigatum A. Br. Am. Jour. Sci. 46: 87. 1844. 
Tyre Locauity: ‘On the banks of the river, below St. Louis,’’ Missouri. 
Rance: British Columbia to New York, south to California, Texas, and Georgia. 
SPECIMENS EXAMINED: West Klickitat County, Suksdorf 2135; North Yakima, Hen- 
derson 2263 and May 26, 1892; White Salmon, Suksdorf 317; without locality, Vasey, 1889; 
Old Fort Colville, Watson 472; Pullman, Piper 1733 and June 20, 1893; Kiona, Cotton 735. 
ZONAL DISTRIBUTION: Arid Transition. 
3. Equisetum variegatum Schleich. Cat. Pl. Helvet. 27. 1807. 
TYPE LOCALITY: Switzerland. 
Rance: Arctic America, south to Nevada and Pennsylvania. 
SPECIMENS EXAMINED: West Klickitat County, Suksdorf 2099. 
4. Equisetum scirpoides Michx. Fl]. 2: 281. 1803. 
TypE Locaity: ‘Hab. in vetustis sylvis Canadae.”’ 
Rance: Alaska to Labrador, south to Washington, Illinois, and Pennsylvania. 
SPECIMENS EXAMINED: Box Canyon, Areager 389; Ione, Kreager 405. 
5. Equisetum arvense L. Sp. P|. 2: 1061. 1753. 
Equisetum saxicola Suksdorf, Deutsch. Bot. Monatss. 19: 93. 1901. 
Type Locatity; “Habitat in Europae agris, pratis.”’ 
Rance: Alaska to Greenland, south to California and New England. Europe. Asia. 
SPECIMENS EXAMINED: Everett, Piper, July, 1892; Skamania County, Suksdorf 2163; 
Falcon Valley, Suksdorf 1238; Pullman, Piper, May 15, 1893; Elmer 210, May, 1897. 
ZONAL DISTRIBUTION: Transition mainly. 
6. Equisetum telmateia Ehrh. Hannov. Mag. 138. 1783. 
Type LocaLity: European. 
Rance: British Columbia to California. Europe. 
SPECIMENS EXAMINED: Seattle, Piper, July 10, 1895; March, 1892; upper Valley Nis- 
qually, Allen 175; Wenache, Whited 19, May 17, 1895; near Bingen, Suksdorf 1237; White 
Salmon, Suksdorf 315. 
ZONAL DISTRIBUTION: Humid Transition. 
