POLYGONACK^. (BUCKWHEAT FAMILY.) 415 



edons slender. — Pedicels jointed. Our.s all herbaceous, nowerin^? thron;;!) Into 

 summer and early autumn. (Name composed of ttoXv, inaiii/, and ■ydi'i;, knee, 

 from the numerous joints.) 

 § 1. BISTORTA, Tourn. Calijx petal-Uhe, dee],!:/ v,-rhfl : stamens 8 or 9 : *■////(.» 



3, slemhr : arlien'ium 3-sided: stems low and sim/Aa J'rom a thick and icaudj 



crcppiivj rootstoch : Jloiccrs in a Sjnke-like raceme. 



1. P. Viviparum, L. (Alpixe Bistort.) Smooth, dwarf (4'-8' liigli), 

 bearing .i linear sjiikc of flesh-coIorcd (lowers (or often little red bulblets in their 

 place) ; leaves lanceolate. — Alpine summits of the White Mountains, Jscw Hamp- 

 shire, shore of Lake Superior, and northward. (Eu.) 



§2. PEKSICaRIA, Tourn. Califx petal-like, b-j>arted : stirjmas capitate: ache- 

 niuin lenticular, or [when there are 3 sliijmas) 3-sided: cotyledons accumbent and 

 albumen hard and hornij except in A'ci. 2 ; roots jibrous : Jlowcrs crowded in 

 spikes or spike-like racemes. 



* Sheaths some of them irith an abrupt spreading and more or lesa follaceons (some- 

 times deciduous) bordir: tall branching annuals, with panickd and nodding dense 

 cylindrical spikes: Jlowers rose or Jlesh-color : achenium flat. 



2. P. orientXle, L. (Prince's Feather.) Soft-hainj ; leaves ovate or 

 oblong, pointed, distinctly pctioled ; flowers large, bright rose-color ; stamens 7 ; 

 style 2-cleft; cotyledons incumbent; albumen floury. — Si^aringly escaped 

 from gardens into waste grounds. (Adv. from India.) 



3. P. Careyi, Olney. Stem (3° -5° high) and peduncles f//aH(//(/o?-7)m//y; 

 leares lanceolate, ronghisli ; flowers jiurplish ; stamens moslly 5 ; style 2-parted. — 

 Shady swamps, Rhode Island to New Jersey, Pennsylvania, and northward. 



* * Sheaths all cylindrical and truncate, without a border. 

 •*- Annuals: spihs oblong or linear, densely Jlowertd: flowers ro.'se or Jlesh-color, or 

 occasionally varying to white, slightly or not at all glandular-dotted : stamens 6 - 8 : 

 styles 2 or 2-cleJl and achenium flattened, except soineliiucs in No. 7, ichich alone 

 has the sheaths at all or more than slightly ciliate. 



4. P. Pennsylvanicum, L. Stem (l°-3°high), smooth below, the 

 branches above, and esjicciully the peduncles, beset with brislly-stalked glands; leaves 

 lanceolate, roughish on the midrib and margins (iV-S'long); sjiikes oblong, 

 obtuse (I' -2' long), erect, thick; stamens mostly 8, somewhat cxserted ; style 2-clefl ; 

 achenium with flat sides. — Moist soil, in open waste places : common. 



5. P. incarnatum, Ell. Nearly glabrous (.30-0° high) ; the peduncles, 

 &c. often minutely rough with scattered sessile glands ; sheaths wholly naked 

 and glabrous ; leaves rough on the midrib and margins, elongated-lanceolate 

 (4' -12' long, l'-3' wide below), tapering gradu:illy from towards the ba.se to a 

 narrow point; spikes linear, nodding, becoming slender (1 j'- 3' long) ; stamens 

 C and styles 2, loth included; achenium with concave sides. (P. nodosum, var. 

 incarnatum, Ed. 2. P. lapathifoiium, Amer. authois, Si-c.) — Wet borders of 

 ponds and streams ; rather common everywhere, especially soutliward and 

 westward. — Flowers smaller than in the last, lighter rose-color, or flesh-color, 

 varying to white. 



6. P. Iapathif61iuni, Ait., is lower, with shorter and muiii less ]>ointed 

 leaves; sheaths often somewhat hairy or ciliolatc ; sjrikes oblong and blittU ; flowers 



