BUCKWHEAT FAMILY 379 



Small, Mem. Columbia Coll. Dept. Bot. 1: 32, pi. 3 (1895). P. polymorphum Ledeb.; Wats. 

 Bot. Cal. 2: 15 (1880). P. phytolaccae folium Meisn.; Small, Bull. Torr. Club, 19: 360 (1892), 

 the type from California; Mem. Columbia Coll. Dept. Bot. 1: 34, pi. 4 (1895). 



3. P. davisiae Brew. Stems simple or sparingly branched, 5 to 11 inches 

 high, several from the crown of a thick taproot 1 or 2 inches in diameter; 

 leaves ovate or oblong- ovate, minutely pubescent, often glaucous, % to l 1 /^ 

 inches long, subsessile or shortly petioled ; flowers purplish green or yellowish, 

 2 to 4 in loose terminal or axillary clusters; achene half exserted from the 

 persistent calyx. 



High mountains, northern Sierra Nevada and North Coast Ranges, 6000 to 



8000 feet. 



Locs. Snow Mt. (ace. Zoe, 4: 175) ; South Yollo Bolly, Jepson; Marble Mt., Jepson 2843; 

 Trinity Summit, Jepson 2053; Salmon Mts., Hall 8619; Mt. Shasta; Lassen Peak, B. M. 

 Austin; Placer Co., Carpenter; Carson Spur, Hansen 714. Mt. Lola, Nev., Kennedy # Doten. 



Eefs. POLYGONUM DAVISIAE Brew. ; Gray, Proc. Am. Acad. 8: 399 (1872), type loc. 

 northern Sierra Nevada, Brewer, Torrey, Miss N. J. Davis; Small, Monog. N. Am. Polygonum, 

 38, pi. 6 (1895). P. newberryi Small; Merriam, N. Am. Fauna, 16: 145 (1899). 



4. P. amphibium L. WATER PERSICARIA. Aquatic glabrous perennial with 

 stout stems not branching above the rooting base ; leaves floating, elliptical to 

 oblong or oblong-lanceolate, truncate or rounded at base, 2 to 7 inches long on 

 petioles % to 2y 2 inches long ; sheaths leaf -bearing at about the middle ; spike 

 terminal, dense, ovate or oblong, y 2 to 1 inch long, on a commonly short 

 peduncle ; calyx bright rose-color, l 1 /^ to 3 lines long, the 5 stamens and 2-cleft 

 style exserted; achene lenticular. 



Ponds and lakes in Southern California and the Sierra Nevada, north to 

 British Columbia and east to the Atlantic. Europe; Asia. Often terrestrial 

 and almost equally successful as a land or water plant. 



Loes. Bluff Lake, San Bernardino Mts., Nora Pettibone; Kern Canon, Jepson 1046; Heteh- 

 Hetchy, Chesnut $ Drew; Lake Tahoe, Brewer 2136; Donner Lake, Heller 7162; Placer Co., 

 Carpenter; Silver Lake, Lassen Co., Baker fy Nutting. 



Var. hartwrightii Bissel. Sheaths rough-hairy, ciliate, usually with an 

 abruptly spreading herbaceous margin. Upper Sacramento Valley and north- 

 ern Sierra Nevada ; eastward to the Atlantic. 



Refs. POLYGONUM AMPHIBIUM L. Sp. PI. 361 (1753), type European; Small, Monog. N. 

 Am. Polygonum, 40, pi. 7 (1895). Persicaria purpurata Greene, Leaflets, 1: 27 (1904), type 

 loc. Silver Lake, Lassen Co., Baiter $ Nutting. P. insignis Greene, 1. c. 32, type loc. San 

 Bernardino Mts., 9550 ft., Wright 1809. Var. HARTWRIGHTII Bissel, Ehod. 4: 105 (1902). 

 Polygonum hartwrightii Gray, Proe. Am. Acad. 8: 294 (1870), type loc. New York, Hart Wright; 

 Greene, Fl. Fr. 136 (1891). 



5. P. muhlenbergii Wats. Perennial, aquatic or in half dry places ; stems 

 decumbent or suberect, 2 to 3 (or 6) feet high; leaves and upper portion of the 

 simple stem usually appressed-hirsutulose or scabrous, the peduncle glandular 

 with short hairs ; leaves thin, ovate-lanceolate to lanceolate, acuminate or even 

 attenuate, usually rounded at base, 3 to 8 inches long, the petioles 1 to 3^2 inches 

 long ; spikes 1 to 4 inches long, often in pairs ; calyx rose-color or pink, 5-parted 

 to the middle; stamens 5, exserted; style 2-cleft; achene lenticular. 



Lakes and sluggish streams from the coast to the Sacramento Valley. 

 Throughout North America. 



Locs. Cache Slough, Solano Co., Jepson; San Francisco, Jepson; Gilroy, Jepson; San Luis 

 Obispo, Jepson 3069; Healdsburg, Alice King; Klamath Eiver, Siskiyou Co., Butler 193; 

 Honey Lake Valley, Davy 3321. 



Refs. POLYGONUM MUHLENBERGII Wats. Proc. Am. Acad. 14: 295 (1879), type from U. S. ; 

 Jepson, Fl. W. Mid. Cal. 161 (1901). P. emersum Britt. Trans. N. Y. Acad. Sci. 8: 73 (1889) ; 

 Small, Monog. N. Am. Polygonum, 44, pi. 9 (1895). Persicaria franciscana Greene, Leaflets, 

 1: 42 (1904), type loc. Mountain Lake, S. F. P. hesperia Greene, 1. e. 43, type loc. Searsville, 

 San Mateo Co., C. F. Baker 1835. P. alismaefolia Greene, 1. c. 44, type loc. Cloverdale, Heller 

 5823. P. covillei Greene, 1. c., type loc. Visalia, Coville $ Funston 1266. 



6. P. lapathifolium L. COMMON KNOTWEED. WILLOW-WEED. Annual, com- 

 monly stout, 1 to 4 feet high, branching; herbage glabrous except a very 



