416 rOLYGOXACE^. (P.UCKAVIIEAT FAMILY.) 



pale or whitish ; style 2-clr/), or not parted to (lie hose. Wc have, sparingly, var. 

 iNcXxLM, Koch (P. incanuin, ]V<lld.), and only a depauperate form of it, 

 3'-C' high; leaves lanceolate, obtuse, white-downy heneath; spikes barely C" 

 long, erect. — Borders of Cayuga Lake, New York (Cliiclceriiig and Breiar), of 

 Lake Su]icrior {0. B. W/icekr) and farther northward (Buimjrau). — The true 

 P. nodosum, Pns., which connects this species with the next, has not been 

 detected. (Ku.) 



7. P. PicKsicVniA, L. (L.vdt's Thumb.) Nearly smooth and glabrous 

 (12'- 18' high); shcallis more or less bristty-ciliate ; leaves lanceolate, pointed, 

 roughish, usually marked with a dark triangular or lunar sjyot near the middle ; 

 spikes ovoid or oblong, dense, erect, on smooth (or at least not glandular) peduncles ; 

 stamens mostly G; styles half 2-5-cl(Jl ; achenium gibbous-flattened or some- 

 times triangular, smooth and shining. — Waste and damp places: very com- 

 mon. — Flowers greenish-purple. (Nat. from Eu.) 



■•- ■*- Annuals or peretmials : spikes slender, Jiliform, loosely-flowered or inter- 

 rupted: flow?7-s greenish or whitish, sometimes purplish-tingrd : sepals dotted 

 with conspicuous glands: leaves pellucid-dotted : sheaths fringed with bristles' 

 whole lurbai/e pungcntly acrid! 



8. P. Hydropiper, L. (Common Smartweed or Water-peitek.) 

 Annual, l°-2° high, smooth; spikes nodding, usually short or interrupted; 

 flowers mostly greenish ; stamens 6; style 2-3-parted ; achenium c?«//, minutely 

 striate, either ^a< or oblusfly triangular. — Woist or wet grounds; apparently 

 introduced eastward, but indigenous northward. (Eu.) 



9. P. ^cre, H. B. K. (Water Smartvv-ked.) /-"e/pHr/Za/, nearly smooth ; 

 stems rooting at the decumbent base, 2° -5° high; leaves larger and longer 

 than in the last, taper-{X)inted ; spikes erect ; flowers whitish, sometimes flesh- 

 color ; stamens 8 ; style mostly 3-partcd, and the achenium sharply triangular, 

 smooth and shining. (P. punctatum, £■//. P. hydropiperoides, PwsA.) — Wet 

 places : common, especially southward. 



••-■'-■*- Pf-rennials, not acrid, aquatic or arujihiliious : sepals not glandular-dotted. 



10. P. hydropiperoldes, Miehx. (Mild Water-Pepper.) Stem 

 smooth (l°-3° high), branching ; the narrow sheaths hairy, fringed with bristles; 

 leaves narrowly lanceolate ; sometimes oblong ; spikes erect, slender, sometimes 

 filiibrm, often interrupted at the base (l'-2^' long); flowers small, flesh-color 

 or nearly white ; stamens 8 ; style 3-clefl ; achenium sharply triangular, smooth and 

 shining. (P. mite, Pers., not of Schrunk.) — Wet places, and in shallow water : 

 common, especially southward. 



11. P. amphibium, L. (Water Persicaria.) Stems somewhat sim- 

 ple, and usually terminated by a single ovate or oblong and very dense spike 

 (6" thick) of rather large briijht rose-nd flowers ; sheaths not fringed with bri.s- 

 tles; stamens h; style 2-clefl ; achenium biconvex; leaves varying greatly, from 

 elliptical or cordate-oblong to lance-ovate or lanceolate. — The ty])ical ])lant is 

 var. aquAticum, Willd. (Var. natans, Ma-nch. P. coccineum, Muhl., &e.), in 

 water, nearly glabrous ; leaves long pctioled, floating, elliptical or oblong, some- 

 times heart-shaped at base ; sjiikes short. — Var. tekuestke, Willd., grows 

 in shallow water, or in wet soil, or even "in sandy prairies" in lUinoia 



