■^^ POLYGONACE.E. Polygonum. 



3 inches long, often in pairs : flowers and fruit nearly as in the last. — P. amphlbium, 

 var. terrestrT,ii\aY, Manual, 416, and others; not of Willdenow. P. a7nphibium, 

 var. (?) Muhlenbergii, Meisner, 1. c. 116. 



In Washington Territory an.l Oregon, and collectecl in ('alifornia {Bloomer) but locality not 

 given exten'ding eastward to the Atlantic Coast and Texas. 



* * Sheaths and bracts bristly ciliate or the sheaths sometimes foUaceously 



margined. 

 ^ Sepals not punctate: style 2-cleft, and ahene somewhat flattened. 



16. P. Hartwrightii, Gray. Perennial, closely allied to the two preceding spe- 

 cies, growing usually lu uiud, the ascending stems rooting at base and very leafy : 

 differTng from the fonu of P. ambignum, growing in like localities, by being more or 

 less rough-hairy, at least on the sheaths and bracts, the former ciliate and often with 

 abruptly spreading foliaceous borders ; leaves rather narrow, 2 to 7 inches long, on 

 very short petioles, adnate to the middle of the sheath. — Proc. Am. Acad. viii. 294. 



Plumas Co. (Jfrs. M. E. P. Ames) ; Utah ( Watson, Ward) ; and eastward through the North- 

 ern States. It varies greatly in hirsuteness and in the characters of the sheath, and when grow- 

 ing in water the lower leaves are thick, smooth, and floating, a[.proaching P. amphibium too 

 closely. 



P Peksic\ri\, Linn. Eesenibling P. nodosum, but sheaths and bracts ciliate ; leaves usually 

 marked by a dark spot near the middle ; spikes short, erect ; flowers shortly pedicelled ; style 

 2-3-cleft, and akene sometimes triangular. — A very common species in the Atlantic States, in- 

 troduced from Europe ; reported from California only in Bot. Beechey. 



^ H_ Sepals conspncnoushf dotted and leaves punctate: style mostly S-jmrted, and 

 akene triangular : juice very acrid. 



17. P. acre, HBK. Perennial, rooting and decumbent at base, 2 to 5 feet high, 

 branching, smooth or somewhat scabrous with short appressed hairs : leaves lanceo- 

 late to ifnear-lanceolate, acuminate, attenuate to a very short petiole : sheaths and 

 the short bracts bristly ciliate : spikes loose and filiform, 1 to 3 inches long, erect 

 on long peduncles : flowers greenish white or purplish, a line long : stamens 8. — 

 :N^ov. Gen. ii. 179 ; Gray, Manual, 416. 



Common in the Atlantic States and ranging to Mexico and South America ; collected in the 

 San Jose Valley {Brewer), but perhaps introduced. 



P Hydfopipek Linn., is an allied annual species, with shorter acute or often obtuse leaves 

 and' more nodding spikes; stamens 6 ; style more frequently 2-parted, and akene consefpiently 

 often compressed.— A Euroi)ean species which also ranges across this continent northward ; found 

 in Washington Territory and perhaps in Northern California. 



§ 4 Glabrous alpine or suhalpine herbaceous perennials, with thick creejnng root- 



stocJcs and simple stems : flowers in dense spike-like racemes : perianth 



colored, deephi r^-r/rft. af leiHjfli appressed to the imonjalar akene: stanirns 



S, with fll i for mfl laments: styles 3, long: leaves puinately eenied : pef,ules 



not, jointed: sheaths obliquely tnincate, naked, as tvell as the scarwus orate 



or ianceolate hracts. — Bistorta, Linn. 



1 8 P Bistorta, Linn. Stems usually a foot or two high : leaves few, the 



radical .jnes on long petioles, oblong-lanceolate to linear, acute at each end, 2 to 8 



inches long, the cauline much reduced, mostly obtuse at base and sessile upon the 



sheath ; the margin often slightly revolute : sheaths elongated : flowers I2 to 2 2 



lines long, rose-colored to white, on slender pedicels, in very dense ovate to oblong 



s .ikes i to U inches long and usually long-pedunculate : bracts ovate, acuminate : 



stamens and styles exserted : akene U lines long, smooth and shining. — Meisner, 



DC. Prodr. xiv. 125. 



Throughout the northern hemisphere ; frequent in meadows and on stream-banks in the Sierra 

 Nevada at 6 -10,000 feet altitude. 



