POLYGONACE^E. (BUCKWHEAT FAMILY.) 415 



cdons slender. Pedicels jointed. Ours all herbaceous, flowering through late 

 summer and early autumn. (Name composed of iro\v, many, and yow, knee, 

 from the numerous joints.) 

 1. BIST6RTA, Tourn. Calyx petal-like, deeply 5-cleft: stamens 8 or 9 : styles 



3, slender : achenium 3-sided : stems low and simple from a thick and woody 



creeping rootstock : flowers in a spike-like raceme. 



1. P. Viviparum, L. (ALPINE BISTORT.) Smooth, dwarf (4' -8' high), 

 bearing a linear spike of flesh-colored flowers (or often little red bulblets in their 

 place) ;. leaves lanceolate. Alpine summits of the WhUe Mountains, New Hamp- 

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



2. PERSICARIA, Tourn. Calyx petal-like, 5-parted: stigmas capitate : ache- 

 nium lenticular, or (when there are 3 stigmas) 3-sided cotyledons: accumbent and 

 albumen Jiard and horny except in No. 2 : roots fibrous : flowers crowded in 

 spikes or spike-like racemes. 



# Sheaths some of them with an abrupt spreading and more or less foliaceous (some- 

 times deciduous) border : tall branching annuals, with panicled and nodding dense 

 cylindrical spikes: flowers rose or flesh-color : achenium flat. 



2. P. ORIENTALS, L. (PRINCE'S FEATHER.) Soft-hairy ; leaves ovate or 

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

 style 2-cieft ; cotyledons incumbent ; albumen floury. Sparingly escaped 

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



3. P. Careyi, Olney. Stem (3 -5 high) and peduncles glandular-bristly; 

 leaves lanceolate, roughish ; flowers purplish ; stamens mostly 5 ; style 2-parted. 

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



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



*- Annuals: spikes oblong or linear, densely Jlowered : flowers rose or flesh-color, or 

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

 styles 2 or 2-cleft and achenium flattened, except sometimes in No. 1 ) which alone 

 has the sheaths at all or more than slightly ciliate. 



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

 branches above, and especially the peduncles, beset with bristly-stalked glands; leaves 

 lanceolate, roughish on the midrib and margins (l'-5' long) ; spikes oblong, 



x obtuse (!' 2' long), erect, thick; stamens mostly 8, somewhat exserted; style 2-clefl ; 

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



5. P. incarnatum, Ell. Nearly glabrous (3 -6 high); the peduncles, 

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

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

 (4' -12' long, l'-3' wide below), tapering gradually from towards the base to a 

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

 6 and styles 2, both included; achenium with concave sides. (P. nodosum, var. 

 incarnatum, Ed. 2. P. lapathifolium, Amer. authors,' ^c.) Wet borders of 

 ponds and streams ; rather common everywhere, especially southward and 

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

 varying to white. 



6. P. Iapathif61ium, Ait, is lower, with shorter and much less pointed 

 leaves ; sheaths often somewhat hairy or ciliolate ; spikes oblong and blunt ; flowers 



