PIPER—FLORA OF THE STATE OF WASHINGTON, 97 
Floating leaves none. 
Leaves all oblong or lanceolate. 
Base of leaves clasping; apex acuminate..........-.-.---- 7. P. perfoliatus. 
Base of leaves not clasping; apex not acuminate. 
Leaves obtuse, cucullate, sessile.. 2.2222. 2222-2--2--- 8. P. praelongus. 
Leaves acute, short-petioled._............-...--..--- 9. P. lucens. 
Leaves all narrowly linear. 
Stipules adnate to the sheathing base of the leaf. 
Leaves setaceous, | to 5-nerved.... 22222-22222... - 13. P. pectinatus. 
Leaves linear-lanceolate, many-nerved................ 14. P. robbinsii. 
Stipules free. : 
Leaves tape-like; spike cylindric; fruit large.......... 10. P. zosteraefolius. 
Leaves not tape-like; spike not cylindric; fruit small. 
Spike capitate; peduncles very short.......-.-.-- 11. P. californicus. 
Spike interrupted; peduncles long. ....--.------- 12. P. pusillus. 
1. Potamogeton natans L. Sp. Pl. 1: 126. 1753. 
TYPE LOCALITY: European, 
Rance: North America. Europe. Asia. 
SPECIMENS EXAMINED: Cascade Mountains, 49°, Lyall in 1859; Oyhut, Lamb 1259; 
Tacoma, Flett 135; Falcon Valley, Suksdorf, July 17, 1886; Pend Oreille River, Lyall in 
1861. 
2. Potamogeton nuttallii Cham. & Schlecht. Linnaea 2: 226. ¢. 6. f. 25. 1827. 
Potamogeton claytoniz Tuck. Am. Journ. Sci. 14: 38. 1843. 
Type Loca.ity: None given. 
Rance: Washington and Oregon to Nova Scotia and South Carolina. 
SPECIMENS EXAMINED: Montesano, Heller 4072; Ilwaco, Henderson in 1886; Lake Wash- 
ington, Piper, September, 1892; Mount Constitution, Henderson 2477; Spokane County, 
Henderson 2476; Waitsburg, Horner R16. 
3. Potamogeton amplifolius Tuck. Am. Journ. Sci. IT. 6: 225, 1848, 
TYPE LocaLity: Cambridge, Massachusetts. 
Rance: British Columbia to Ontario, south to Washington and Nebraska. 
SPECIMENS EXAMINED: Coupeville, Gardner 421; Pullman, Henderson 2474; Kalispel 
Lake, Areager 441; Whatcom County, Suksdorf, August 1, 1890. 
4. Potamogeton alpinus Balbis, Mem. Acad. Turin 7: 323. 1803. 
Potamogeton rufescens Schrad.; Cham. Ad. FI. Ber. 5, 1815. 
TYPE LOCALITY: European. 
Rance: British Columbia to Labrador, south to California and New Jersey. 
SPECIMENS EXAMINED: Mount Adams, Suksdorf, September, 1879; Trout Creek, Suks- 
dorf 2172. 
5. Potamogeton heterophyllus Schreb. Spicileg. Fl. Lips. 21. 1771. 
Tyee Loca.ity: ‘‘In stagno ad Lindenthal,” Germany. 
Rance: Throughout most of North America. Europe. 
SPECIMENS EXAMINED: Lake Chelan, Lake & Hull 614; Okanogan River, Watson 396; 
Tumwater Canyon, Sandberg & Leiberg 524; Faleon Valley, Suksdorf, August, 1885. 
6. Potamogeton lonchites Tuck. Am. Journ. Sci. 11. 6: 226. 1848. 
Type Locauity: “Common in New England and extending southward to Virginia.” 
Rance: Washington to New Brunswick, south to California and Florida. 
SPECIMENS EXAMINED: Clallam County, Elmer 2798; Silver Lake, Henderson 2475; 
Okanogan River, Watson 398; Pend Oreille River, Lyall in 1861; Whitman County, Hen. 
derson 2473; Union Flat, Paper, August 4, 1899, without locality, Vasey in 1889. 
29418—06 m——7 
