POLYGONACEuE. (bTTCKWHEAT FAMILY.) 415 



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

 summer and early autumn. (Name composed of jroKv, many, and yon, knee, 

 from the numerous joints.) 



§ 1. B1ST6ETA, Tourn. Cali/x pdal-Ulce, deeply 5<kft: stamens 8 or 9 : styles 

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

 creeping rootstock : flowers in a spike-like raceme. 



1. P. viviparum, L. (Alpine Bistokt.) Smooth, dwarf (4' -8' high), 

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

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

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



§ 2. PERSICA.RIA, Tourn. Calyx petal-lilce, 5-paried: stigmas capitate : ache- 

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

 albumen lutrd and homy except in No. 2 ; roots flbrous : flowers crowded in 

 spikes or spikerlike racemes. 



* Sheaths some of tliem. with an abrupt spreading and more or less fl>liaceous (some- 

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

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



2. P. orientAle, L. (Priucb's Feather.) Sofi-liairy; leaves ovate or 

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

 style 2-cleft ; cotyledons incumbent ; albumen floury. — Sparingly escaped 

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



3. P. Ctoeyi, Olney. Stem (3°-5"' high) and pedunclesjZani^Mfar-Jn'si/'j/; 

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

 Shady swamps, Rhode Island to the mountains of Pennsylvania, and northward. 



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

 ■♦- Annuals: spikes oblong or linear, densely flj3wered: 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. 7, which alone 

 has the sheaths at all or more than slightly ciliate. 

 i. P. Pennsylv^nicum, L. Stem (l°-3°high), smooth below, the 

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

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

 obtuse (l'-2' long), erect, thick; stamens mostly 8, somewhat exserted; style 2-defl; 

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



5. P. iucarn^tum, Ell. Nearly glabrous (3° -6° 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 gradually from towards the base to a 

 narrow point; spikes linear, norfrfin^, becoming slender (lJ'-3' long) ; stamens 

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

 incamatum, 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. lapathifblium, Ait, is lower, with shorter and much less pointed 

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



