440 POLYGONACE^. (BUCKWHEAT FAMILY.) 



3. P. erectum., L. Stouter, erect or ascending (1 -2° high), //c/Zotf/sA; 

 leaves oblong or oval {-1^-2^' long), usually obtuse; y?0M-ers mostlii \^" lomj, 

 often yellowish, on more or less exserted pedicels ; stamens 5 - 6 ; achene dull, 

 included. (P. aviculare, var. erectum, Roth.) — Common, by -waysides, etc. 



* * Leaves much reduced above and bract-like. 



4. P. ramosissimum, Michx. Erect or ascending (2-4° high), yel- 

 lowish-green; leaves lanceolate to linear (1-2^' \on^), acute; Jlowers and 

 achene as in n. 3, but sepals more frequently 6, the stamens 3-6, and the 

 achene mostly smooth and shining. — Sandy shores and banks of streams, E. 

 Mass. to N. Y., west to Minn., Ark., Tex., and far westward. 



5. P. tenue, Michx. Stem angled, erect (i-H° high), glabrous, or 

 slightly scabrous at the nodes; leaves narrowly linear to lanceolate (1-2' 

 long), 3-nerved, acute at each end and often cuspidate, the margins somewhat 

 scabrous and at lengtli revolute; Jloicers often solitary, ?iea//// sessile; stamens 

 8; achene included, dull black. — Dry soil, N. Eng. to S. C, west to Minn., 

 Mo., and Te.x. 



6. P. camp or um, Meisn. Stem /ere/e, erect or ascending (2-3° high), 

 glabrous; Uaves deciduous, Imeur to oblong, usually short ; pedicels slender, 

 exserted from the scarious sheaths; stamens 8. — E. Kan. to Tex. 



§2. PERSICAKIA. Flowers in dense spikes, icith small scarious bracts; 

 leaves not jointed on the petiole ; sheaths ci/lindrical, truncate, entire, naked 

 or ciliate-f ringed or margined ; cali/x colored, h-parted, appressed to the 

 fruit; stamens i -S; Jilaments Jillform ; cotyledons accumbent. 

 * Sheaths and bracts not ciltate or fringed ; sepals not punctate ; style 2-cleJl. 



7. P. lapathifblium, E. Annual, branching, 1-4° high, glabrous or 

 the peduncles often minutely glandular ; leaves lanceolate, attenuate upward 

 from near the cuneate base and acuminate, someAvhat scabrous with short ap- 

 pressed hairs on the midrib and margin, or rarely floccose-tomentose beneath; 

 sheaths and bracts rarely somewhat ciliolate •, spikes oblong to linear (^-2' 

 long), dense, erect or nearly so; flowers white or pale rose-color; stamens 6; 

 achene ovate, rarely \" broad. (P. nodosum, Pers. P. incarnatum, Man., in 

 part.) — Wet places ; N. Eng. and Can. to 111., Wise, and far westward. Very 

 variable. (Eu.) 



Var. incarnatum, Watson. Eeaves often large (6-12' long, 1 - 3' wide) ; 

 spikes more slender and elongated (2-4' long), nodding. (P. incarnatum, 

 Ell.) — Penn. to 111., Mo., and southward. 



Var. incanum, Koch. Low (6-12' high) ; leaves small, obtusish, more 

 or less hoary beneath with floccose tomentum ; spikes short. — Cayuga Lake, 

 N. Y., Ont., shores of L. Superior, and northwestward (Eu.) 



8. P. Pennsylvanieum, L. A similar species, but the branches above 

 and especially the peduncles beset with stipitate glands ; flowers larger and often 

 bright rose-color, in short erect spikes, often on exserted pedicels; stamens 

 usually 8; achene nearly orbicular, over 1" broad. — Moist soil, in open waste 

 places, common. 



9. P. amphibium, L. Perennial, aquatic or rooting in the mud, stout 

 and glabrous or nearly so, not branching above the rooting base; leaves usu- 

 ally Jioaling, thick, smooth and shining above, mostly loug-petioled, elliptical 



